WARSAW -- US President Joe Biden on Saturday met with Ukraine's Foreign Minister Dmytro Kuleba and Defence Minister Oleksii Reznikov during his visit to Poland, "for an update on Ukraine's military, diplomatic, and humanitarian situation," according to the White House.

Biden dropped in a meeting between US Secretary of State Antony Blinken and Secretary of Defense Lloyd Austin and their Ukranian counterparts, Kuleba and Reznikov.

They discussed "further efforts to help Ukraine defend its territory" and the United States and its allies' ongoing actions towards Russia, the White House said in statement.

In a tweet, Kuleba said that the meeting between Ukrainian ministers and US secretaries allowed him to seek "practical decisions in both political and defense spheres in order to fortify Ukraine's ability to fight back," while Reznikov tweeted that he acquired "cautious optimism."

Biden is visiting Poland, after attending the North Atlantic Treaty Organization (NATO) summit, G7 gathering and the summit of the European Council -- three intensive summits in two days with the Ukraine crisis as major focus.

The US president tried to coax a display of unity with European partners, but failed to talk them into concerted actions against Russia.

The NATO summit concluded Thursday with no agreement to impose additional sanctions against Moscow, especially the country's oil and gas products. Nor did the European Council summit succeed in reaching a consensus on the same issue.