Prime Minister Scott Morrison has lashed out at Russian aggression on the Ukraine border, as Australian diplomatic staff evacuate from the embassy in Kyiv.

As tensions in the region heighten, Mr Morrison said it was time for Australia to stand up to countries that bully Ukraine.

“We denounce Russia’s bullying, coercion, intimidation and threats of violence against Ukraine, and we will always take steps to do that,” he told parliament.

“We look on these issues and these events with great concern, we support Ukraine’s sovereignty, we support their right to territorial borders, and that they not be imperilled.”

The US has warned a Russian invasion of Ukraine is imminent. There are some reports it is expected on Wednesday, but American authorities have refused to confirm that.

Earlier on Monday, a Senate estimates hearing was told 147 Australian citizens were still in Ukraine.

Travel advice for Australians in Ukraine has been to leave the country immediately.

Diplomatic staff who had been stationed in Kyiv have been directed to a temporary office in Lviv in Ukraine’s west.

Acting deputy secretary national security and international policy Rod Brazier told Senate estimates the final five remaining staff members had arrived in Lviv on Sunday.

“(Sunday) morning as a result of the threat to peace and stability in the region, the Australian embassy in Kyiv was temporarily closed,” he said.

“The embassy has set up a facility for operations. This is a temporary move that will be kept under review considering the security situation.”

The prime minister said the situation in Europe was increasingly uncertain.

“It is time to stand up against those who seek to bully, whether it is Australia, Lithuania or indeed Ukraine,” he said.

“It is time to stand up to the bullies, to the autocrats who work together.”

Trade Minister Dan Tehan said Australia would enact strong economic sanctions against Russia should an invasion be carried out.

“We want a de-escalation, but if (invasion) happens, then you’ll be looking at sanctions and we’ll be a part of that,” he said.

Mr Tehan said an invasion would also likely lead to an increase in oil and gas prices and put pressure on international markets.

Treasurer Josh Frydenberg said the situation in Ukraine had reached a “dangerous juncture”.

“It’s a very dangerous situation and the reverberations will be felt far and wide if, in fact, the Russians do invade,” Mr Frydenberg told the Nine Network.

“You don’t amass more than 100,000 troops on a border to check out the views or have a picnic.”

-AAP