Japanese Prime Minister Shinzo Abe and US President Barak Obama agreed to closely cooperate on the situation in Ukraine in a telephone conversation on Friday.

In the 40-minute phone talks, Abe said that he "supports Mr. Obama's efforts to improve the situation in Ukraine," the Japanese Foreign Ministry said.

The two leaders also agreed to work through the International Monetary Fund (IMF) to assist economic and political reforms in Ukraine, said the ministry.

Japanese Foreign Minister Fumio Kishida said earlier in the day that Tokyo will study possible financial assistance for Ukraine through the IMF.

Meanwhile, the White House said that Obama and Abe "emphasized the importance of preserving Ukraine's sovereignty and territorial integrity," and agreed that Russia's actions in Ukraine threaten world peace and security.

Despite the harsh criticism, Kishida refused to say whether Japan would impose sanctions on Russia over the use of its armed forces in Ukraine.

"Our country will deal with the issue appropriately while closely monitoring the situation in Ukraine and the movements of other countries," he said, urging Moscow to hold "political talks" with Ukraine's new pro-Western government.

The Abe administration is trying to develop closer ties with Russia and hoping to solve a decades-old territorial dispute with Moscow.