The allies agreed on the necessity of "increasing Moscow's international isolation", the government added in a statement.

The decision was taken during a virtual meeting dedicated to Moscow's invasion of Ukraine between US President Joe Biden and allies including French President Emmanuel Macron, British Prime Minister Boris Johnson, and German Chancellor Olaf Scholz.

EU chiefs Ursula von der Leyen and Charles Michel, NATO head Jens Stoltenberg and the leaders of Canada, Italy, Romania, and Poland also took part.

"We will further tighten our sanctions against Russia and step up financial and security assistance for Ukraine," European Commission chief Ursula von der Leyen wrote on Twitter.

The Italian government statement also reaffirmed a common commitment to diversifying energy sources and reducing dependence on Russian supplies.

The latest round of Western diplomacy comes after Russia launched a new phase of its war in Ukraine in the eastern Donbas region.

Ukrainian President Volodymyr Zelensky on Monday said Russia had begun its eastern offensive after Moscow withdrew troops from the region around the capital Kyiv.

Pro-Moscow separatists have controlled parts of the Donbas since 2014 in two self-proclaimed republics in the Donetsk and Lugansk regions.