Australia's estranged ambassador to Ukraine would be returned to the capital Kyiv under a coalition government.
Australia's embassy was moved to Poland when Russia invaded Ukraine, due to safety fears.
Opposition foreign affairs spokesman Simon Birmingham said some 70 countries had reopened embassies in Ukraine showing it could be done safely.
Australia was missing out on access to officials and intelligence briefings that were often conducted with little notice and couldn't be accessed remotely, he said.
"Reopening Australia's embassy would send a strong and positive message of support for Ukraine," he said as he visited Kyiv on Thursday.
Early warning and air defence systems had rendered Russian assaults "largely ineffective for large parts of the country, including the capital", he said.
"Of course, people are on alert for their safety ... (but) on the whole, they are getting on with business, getting on with ensuring that this country is as strong as possible to repel the Russian invasion."
Foreign Affairs Department secretary Jan Adams has repeatedly defended the decision to keep the embassy closed as the war dragged into its third year, saying she continued to assess security.
Ukraine remained "an unpredictable situation" and the department had to operate under Australian law, she told a parliamentary inquiry.
Diplomats were able to do their job effectively from Poland, she added.
Australia continues to pay rent for a shared embassy with Canada in Kyiv under a rolling contract.
Senator Birmingham will meet with Ukrainian government ministers and parliamentarians as well as observe humanitarian programs during his trip.
Australia needed to be one of Ukraine's biggest supporters he said, as he called for the government to offer more military support and energy assistance after Kyiv requested coal.
Australia has provided more than $1 billion in military support to Ukraine since Russia's invasion in February 2022, including Bushmasters, anti-tank weapons, air defence missiles, artillery and ammunition.
