The US national security adviser, Jake Sullivan, urged all Americans still in Ukraine to leave in the next 24 to 48 hours, citing the danger of a potential Russian invasion, writes The Guardian.

“We obviously cannot predict the future. We don’t know exactly what is going to happen”, Sullivan said at the White House press briefing.

“But the risk is now high enough and the threat is now immediate enough that this is what prudence demands. If you stay, you are assuming risks with no guarantee that there will be any other opportunity to leave”.

Sullivan added that there would be “no prospect of a US military evacuation in the event of a Russian invasion” so American citizens need to make plans to leave the country immediately.

“If a Russian attack on Ukraine precedes, it is likely to begin with aerial bombing and missile attacks that could obviously kill civilians without regard to their nationality”, Sullivan said.