The state department has ordered relatives of US government employees based in Nicaragua to leave the Central American country.
Services at the US embassy in the capital in Managua will be curtailed.
The order comes after days of deadly rioting triggered by planned changes to Nicaragua's social security system.
Even though Nicaraguan leader Daniel Ortega had scrapped the changes, the situation remains tense and more protests are expected.
The state department also said it would authorise US government personnel to leave Nicaragua but that those decisions would have to be taken on a case-by-by-case basis.
In a statement it warned that "political rallies and demonstrations are occurring daily, often with little notice or predictability".
"Some protests result in injuries and deaths," it says, adding that buying food and fuel could become a challenge and access to the airport in Managua could be blocked.
A human rights group says at least 27 people have been killed in total as a result of the unrest, more than double the official death toll of 10.
How did it all start?
The unrest first started on Wednesday when hundreds of people, mainly pensioners, took to the streets of the capital, Managua, to protest against changes to the country's social security system.
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The protesters and some of the journalists covering the demonstration were set upon by men wearing motorcycle helmets who beat them with metal pipes and electric cables.
Some local media said those beating up the protesters were part of pro-government gangs and were wearing T-shirts with pro-government slogans.
How did it escalate?
On Thursday, students and employers joined the protesting pensioners in several cities, boosting the numbers of demonstrators to thousands rather than hundreds. There were also further stand-offs between the protesters and pro-government groups.
Students took over the National University of Engineering and confronted riot police, who fired tear gas and rubber bullets.
The protests spread from Managua to a dozen other cities across the country.
On Friday, the army was deployed to guard government buildings and the protests turned deadly with several people, including two protesters and a policeman, killed.
The security forces were accused of using excessive force to contain the protests, which had started peacefully.
But First Lady Rosario Murillo, who is also the country's vice-president, defended the response, saying it constituted a "legitimate defence against a tiny group" of troublemakers.
Over the weekend, protests escalated further with a reporter shot dead during a live broadcast in the town of Bluefields on the Caribbean coast.
Some took advantage of the chaos to loot shops, while shopkeepers armed themselves and stood guard around their businesses.
What were the proposed changes?
The changes were aimed at boosting Nicaragua's troubled social security system, which has been running on a deficit.
Pensioners would have had to pay 5% of their pensions into a fund for medical expenses.
Employees would have had to contribute a larger chunk of their salary towards social security – 7% instead of the current 6.25%. And employers, too, would have had to pay more money into the social security pot.
The changes were due to come into force on 1 July.
Are the protests only about social security?
The protests were triggered by the proposed changes but the harsh response to what started as peaceful demonstrations brought many more people onto the streets.
There was also outrage over the fact that journalists were among those killed. A number of TV stations also complained of censorship after they were taken off the cable network.
Miguel Mora, the director of 100% Noticias, one of the stations to be taken off air, wrote on Facebook: "They are threatening us!"
The protests also appear to have grown into a bigger anti-government movement, with protesters expressing their anger at the president's increasingly authoritarian style.
Is the scrapping of the measure likely to calm matters?
For those whose main concern was the increase in social security payments, its scrapping will be seen as a victory and it may satisfy them.
But the anti-government protests, the largest in decades, have emboldened many Nicaraguans to speak out more freely against President Daniel Ortega and his influential wife and vice-president.
There has been discontent with the president, who is on his third consecutive term in office, for years in some parts of society.
The 2014 scrapping of presidential term limits has been seen as a threat to democracy and some of those who have been demonstrating have accused Mr Ortega and his wife of having "dictatorial tendencies".
The business community has said it will not sit down for talks with the government until police violence stops and freedom of speech is restored.
Protesting students have demanded that those arrested during the demonstrations be freed.
The state department has ordered relatives of US government employees based in Nicaragua to leave the Central American country.
Services at the US embassy in the capital in Managua will be curtailed.
The order comes after days of deadly rioting triggered by planned changes to Nicaragua's social security system.
Even though Nicaraguan leader Daniel Ortega had scrapped the changes, the situation remains tense and more protests are expected.
The state department also said it would authorise US government personnel to leave Nicaragua but that those decisions would have to be taken on a case-by-by-case basis.
In a statement it warned that "political rallies and demonstrations are occurring daily, often with little notice or predictability".
"Some protests result in injuries and deaths," it says, adding that buying food and fuel could become a challenge and access to the airport in Managua could be blocked.
A human rights group says at least 27 people have been killed in total as a result of the unrest, more than double the official death toll of 10.
How did it all start?
The unrest first started on Wednesday when hundreds of people, mainly pensioners, took to the streets of the capital, Managua, to protest against changes to the country's social security system.
Media playback is unsupported on your device
The protesters and some of the journalists covering the demonstration were set upon by men wearing motorcycle helmets who beat them with metal pipes and electric cables.
Some local media said those beating up the protesters were part of pro-government gangs and were wearing T-shirts with pro-government slogans.
How did it escalate?
On Thursday, students and employers joined the protesting pensioners in several cities, boosting the numbers of demonstrators to thousands rather than hundreds. There were also further stand-offs between the protesters and pro-government groups.
Students took over the National University of Engineering and confronted riot police, who fired tear gas and rubber bullets.
The protests spread from Managua to a dozen other cities across the country.
On Friday, the army was deployed to guard government buildings and the protests turned deadly with several people, including two protesters and a policeman, killed.
The security forces were accused of using excessive force to contain the protests, which had started peacefully.
But First Lady Rosario Murillo, who is also the country's vice-president, defended the response, saying it constituted a "legitimate defence against a tiny group" of troublemakers.
Over the weekend, protests escalated further with a reporter shot dead during a live broadcast in the town of Bluefields on the Caribbean coast.
Some took advantage of the chaos to loot shops, while shopkeepers armed themselves and stood guard around their businesses.
What were the proposed changes?
The changes were aimed at boosting Nicaragua's troubled social security system, which has been running on a deficit.
Pensioners would have had to pay 5% of their pensions into a fund for medical expenses.
Employees would have had to contribute a larger chunk of their salary towards social security – 7% instead of the current 6.25%. And employers, too, would have had to pay more money into the social security pot.
The changes were due to come into force on 1 July.
Are the protests only about social security?
The protests were triggered by the proposed changes but the harsh response to what started as peaceful demonstrations brought many more people onto the streets.
There was also outrage over the fact that journalists were among those killed. A number of TV stations also complained of censorship after they were taken off the cable network.
Miguel Mora, the director of 100% Noticias, one of the stations to be taken off air, wrote on Facebook: "They are threatening us!"
The protests also appear to have grown into a bigger anti-government movement, with protesters expressing their anger at the president's increasingly authoritarian style.
Is the scrapping of the measure likely to calm matters?
For those whose main concern was the increase in social security payments, its scrapping will be seen as a victory and it may satisfy them.
But the anti-government protests, the largest in decades, have emboldened many Nicaraguans to speak out more freely against President Daniel Ortega and his influential wife and vice-president.
There has been discontent with the president, who is on his third consecutive term in office, for years in some parts of society.
The 2014 scrapping of presidential term limits has been seen as a threat to democracy and some of those who have been demonstrating have accused Mr Ortega and his wife of having "dictatorial tendencies".
The business community has said it will not sit down for talks with the government until police violence stops and freedom of speech is restored.
Protesting students have demanded that those arrested during the demonstrations be freed.
