President Barack Obama, in telephone talks on Feb 9, urged Prime Minister Shinzo Abe to refrain from visiting Russia in May, as Washington seeks to isolate Moscow over its actions in Ukraine and Syria, sources close to Japan-Russia relations said Tuesday.

But Abe refused to comply with Obama's request, and intends to proceed with plans to travel to Sochi, Russia, around early May for talks with Russian President Vladimir Putin, according to the sources.

Abe and Obama spoke by phone two weeks ago primarily to discuss cooperation between Japan and the United States in responding to the launch of a rocket by North Korea two days earlier. The Japanese Foreign Ministry has not publicly revealed what the two leaders discussed regarding Abe's trip to Russia.

However, the sources quoted Obama as urging Abe to give up his Russia trip for now, citing Russia's differences with the United States over the handling of the Ukrainian and Syrian issues.

Abe is keen to settle a long-standing bilateral dispute over Russian-held, Japanese-claimed islands off Hokkaido that has prevented the two countries from signing a peace treaty after World War II. The islands-Etorofu, Kunashiri, Shikotan and the Habomai group of islets-were seized by the Soviet Union following Japan's surrender on Aug 15, 1945.

One source said Abe "will push through with his trip to Russia in May whatever the United States says" and that Abe told Obama that resolving the territorial dispute will contribute to stability in the East Asian region.

While seeking to find a breakthrough over its territorial dispute with Russia, Japan has been careful to maintain a delicate balancing act between Russia and United States, its key ally, political observers say.

Source: Japan time