Prime Minister Scott Morrison has held talks with UK counterpart Boris Johnson, with the British leader pledging a $47 million security package as part of a defence agreement between the two nations.
The two leaders met virtually on Thursday morning, where the pair discussed the ongoing tensions in Ukraine.
In a joint statement, the leaders emphasised Ukraine's sovereignty and independence, amid Russian troops amassing on the border.
"They agreed the need for de-escalation and underscored that any further Russian incursion in Ukraine would be a massive strategic mistake and have stark humanitarian cost," the statement said.
"The leaders reiterated their commitment to support a rules-based international order free from coercion, where the sovereign rights of all nations are respected."
As part of the discussions, Mr Johnson pledged $47 million from the UK in order to strengthen resilience in the Indo-Pacific region in areas such as maritime security, state threats and cyberspace.
Both leaders pledged they would work closely alongside ASEAN and other partners in the region.
The arrangement comes just months after the creation of the AUKUS security pact between Australia, the UK and US.
"The prime ministers expressed their determination to continue to work closely together, in lockstep with President Biden, to make AUKUS a success," the statement said.
The next round of trilateral talks as part of AUKUS will take place at the end of February in Australia.
In addition to talks on Ukraine, both leaders discussed tensions in the Taiwan Strait, expressing support for Taiwan to take part in international organisations as a member where statehood is not a prerequisite.
"Leaders recognised the importance of countries being able to exercise their maritime rights and freedoms in the South China Sea," the joint statement said.
"Leaders reiterated their strong opposition to any unilateral actions that could escalate tensions and undermine regional stability."
The free-trade agreement between the two countries, the first the UK signed since it left the European Union, was also brought up during the conversation between the two leaders.
Plans were also discussed for investment opportunities to boost Australia's critical minerals sector and the UK's manufacturing and energy targets.
Both leaders also committed to increase joint naval exercises in the Indo-Pacific.
Mr Morrison said he welcomed the UK's "Indo-Pacific tilt".
During the talks, Mr Morrison and Mr Johnson pledged to work together to help both nations reach net-zero by 2050 climate targets
Aid to Tonga by Australia and the UK was also discussed, following the Pacific nation's damaging underwater volcanic eruption and resulting tsunami.