The United States has reiterated its call for American citizens to “immediately” leave Russia after Moscow announced a partial mobilisation to draft soldiers to fight in Ukraine.

In a security alert issued late on Tuesday (September 27), the US Embassy in Moscow said Americans should make their own arrangements to get out of the country “as soon as possible”.

“Russia may refuse to acknowledge dual nationals’ US citizenship, deny their access to US consular assistance, prevent their departure from Russia, and recruit dual nationals for military service,” the alert said.

The US Department of State had called on US citizens to leave Russia in March, amid growing tensions between Washington and Moscow over the invasion of Ukraine.

The US travel advisory for Russia, last updated in August, states that US citizens should leave the country due to “arbitrary enforcement of local law”, as well as the US embassy’s limited ability to assist Americans in the country, potential harassment and “terrorism”.

“Exercise increased caution due to wrongful detentions,” the advisory states.

Two Americans – basketball star Brittney Griner and former US Marine Paul Whelan – are currently imprisoned in Russia on drug and espionage charges, respectively.

The administration of US President Joe Biden considers them wrongfully detained.

The US embassy in Moscow also warned citizens against participating in demonstrations in Russia.

“We remind US citizens that the right to peaceful assembly and freedom of expression are not guaranteed in Russia,” the alert said.

“Avoid all political or social protests and do not photograph security personnel at these events. Russian authorities have arrested US citizens who have participated in demonstrations.”

Last week, Russian President Vladimir Putin announced a partial military mobilisation, calling up as many as 300,000 army reservists to serve in Ukraine.

Russia launched the invasion of its neighbour in February after a months-long standoff that saw Putin demand an end to NATO expansion into former Soviet republics.

But Moscow’s military campaign has been mired by setbacks. In recent weeks, Ukrainian forces, backed by US weaponry, recaptured large swaths of territory in a counteroffensive in the east of the country.

Earlier this month, Russian-installed officials in four occupied regions of Ukraine held votes to join Russia.

Washington has condemned what it calls the “sham” referendums and vowed to never recognise Russia’s expected annexation of the territories.

“Ukraine has the absolute right to defend itself throughout its territory, including to take back the territory that has been illegally seized one way or another by Russia,” US Secretary of State Antony Blinken said on Tuesday.

Meanwhile, US officials say they will continue with their sanctions campaign against Moscow over the invasion.

James O’Brien, the State Department’s head of sanctions coordination, told US lawmakers today (September 28) that “everything is on the table” when it comes to future measures against Moscow.

“There will be more packages,” O’Brien said. “We are working on more sanctions.”