The US walking back support for Ukraine has sent "tectonic changes" through the international system, the Ukrainian ambassador says as he calls for more aid.
Washington remaining a strong security partner to Europe was crucial for security and a step back would raise questions about its commitment to the Pacific and other parts of the world, Vasyl Myroshnychenko said.
Kyiv would work with any incoming Australian government following the federal election, as it requests more support in the form of armoured Bushmaster vehicles and more tanks due to be decommissioned, he said.
The US Patriot missile defence system was integral to Ukraine's defence and was the only way to stop Russian ballistic missiles, he said when asked about a military capability gap if support from the White House ended.
Any peace deal between Kyiv and Moscow needed to include deterrence against future Russian aggression, the ambassador said.
"The presence of a military is a must," he said.
"It could be boots on the ground, it could be some conventional weapons located in Ukraine - we need to deter any future Russian aggression," he told ABC TV on Wednesday.
Mr Myroshnychenko welcomed Prime Minister Anthony Albanese's comments about considering any requests for Australian peacekeepers.
"Certainly we're in discussions with the government about what else could be done to support Ukraine," he said.
Australian aid should be seen as an investment in its own security as defending liberal democracies, human rights and the rule of law stopped the descent into a global system ruled by military strength, Mr Myroshnychenko said.
"If we get into the world of a jungle, where might is right, it will be very difficult for everybody, including Australia," he said.
"So we believe it's in a strategic national interest for Australia to continue supporting us."
Defence Minister Richard Marles said any request for boots on the ground would be considered when it came through.
"We do have a history of engaging in peacekeeping around the world, and there are Australians, servicemen and women right now who are engaged in peacekeeping in places such as the Middle East," he told Nine's Today Show.
"Obviously contingencies are being worked up, but I think the important point to make is we will stand ready to assist."
The ambassador invited Australian companies to invest in Ukraine's critical mineral sector as Kyiv looks to sign a deal with Washington despite a spat between President Volodymyr Zelenskyy and US President Donald Trump.
But security guarantees were needed "because no private or public investment is going to come into Ukraine if we don't have rock solid guarantees", Mr Myroshnychenko said.
