Ukrainian president discusses threat posed by Russia with his Polish counterpart

A major topic of the meeting between Poland's Andrzej Duda and Ukraine's Volodymyr Zelenskiy was a Russian military build-up near Ukraine's border, which posed "a huge threat for a large part of the continent", Duda's foreign affairs advisor Jakub Kumoch said.

"Poland supports Ukraine, we say very strongly there will be no acceptance of Russia's aggressive policy, and we oppose any concessions to Russia as we believe that Ukraine deserves solidarity from the western world and NATO," Kumoch added.

"The presidents of Poland and Ukraine are having consultations here at the invitation of President Andrzej Duda. It's very important to us bearing in mind the context of this meeting, the risks that Ukraine faces today and the tension at the Ukrainian border," said Andriy Sybiha, chief of Zelenskiy's office.

"The main topic of today's round of talks is security, including energy security. We'll talk about coordinating our policies as far as the Nord Stream 2 pipeline and we'll discuss how to strengthen our capability in terms of defence to make our countries more resilient because I believe that together we are stronger," he added.

Russia has massed tens of thousands of troops on its borders with Ukraine, and Western states fear Moscow is planning a new assault on the country.

Russia denies it is planning an attack, but says it could take unspecified military action if a list of demands is not met.

"Productive talks with my friend Andrzej Duda are underway. Discussed security challenges, lifting obstacles in the transport sphere, enhancing energy interaction. Agreed on a further schedule of meetings," Ukrainian President tweeted.

U.S. President Joe Biden said on Thursday that he has made clear to Russian President Vladimir Putin that any movement of Russian military forces into Ukraine will be considered an invasion. Speaking to reporters, Biden said that Russia would pay a heavy price in the event of an invasion and that the United States has prepared broad sanctions to impose should that happen.

The United States and its European allies will present a united front if Russia further acts against Ukraine, U.S. Secretary of State Antony Blinken told reporters on Thursday following his meetings with German officials. Blinken, speaking alongside his German counterpart, said Moscow would be met with a "swift... severe" united response should its forces cross into Ukraine. Additionally, Washington and its partners would present a united response in any possible sanctions and were working on a coordinated response toward any other possible destabilizing actions Russia may take, he said.