Australia has directed all remaining embassy staff in Kyiv to evacuate, Prime Minister Scott Morrison said Sunday, as Russia continued to build up troops on its border with Ukraine.

The evacuation follows similar announcements from the United States and Canada, and comes after a frenzy of telephone diplomacy failed to ease mounting regional tensions Saturday.

Russia has nearly surrounded its western neighbour with more than 100,000 troops.

Tensions intensified after Washington warned that an all-out invasion could begin “any day” and Russia launched its biggest naval drills in years across the Black Sea.

Morrison said Australia would shift its operations to Lviv, a city close to Ukraine’s border with Poland that is about 540 kilometres (336 miles) east of Kyiv.

He said the three remaining staff in Kyiv had been supporting “the many Australians [in Ukraine], many of whom are dual citizens”.

“The situation, as you are all hearing, is deteriorating, and is reaching a very dangerous stage,” he said.

While decrying “the autocratic, unilateral actions of Russia”, the prime minister also pivoted back to regional politics, criticising China for “remaining chillingly silent on Russian troops amassing on the Ukrainian border”.

“The coalition of autocracies that we’re seeing, seeking to bully other countries, is not something that Australia ever takes a light position on,” Morrison said.

Australia Foreign Minister Marise Payne reiterated calls for Australians to leave Ukraine immediately, warning that “security conditions could change at short notice.”