A senior U.S. diplomat cautioned Japan on Thursday against seeking closer ties with Russia, given that both Washington and Tokyo have imposed sanctions on the country over its annexation last year of Crimea, southern Ukraine.

Daniel Russel, assistant secretary of state, told a news conference in Washington that he was confident that the Abe government is “committed to the principle of not pursuing business as usual (with Russia) under the current circumstances.”

Prime Minister Shinzo Abe had told U.S. President Barack Obama during their summit last month he might try to invite Russian President Vladimir Putin to Japan later this year, according to government sources in Tokyo.

Russel dismissed the view that last week’s meeting between U.S. Secretary of State John Kerry and Putin hinted at any form of change in U.S. policy on Russia over the Ukrainian crisis.

Washington notified Tokyo in advance of Kerry’s plan to meet with Putin in Sochi, Russia, so “there was no surprise and I certainly hope no misunderstanding,” Russel added.

Kerry met with Putin to ensure that a February cease-fire agreement between the Ukrainian government and pro-Russia militants will be implemented, Russel said.

The Abe government had hoped to invite Putin in the fall of 2014, hoping it would lead to progress in stalled negotiations on a territorial dispute that has prevented the two countries from concluding a post-World War II peace treaty. But the plan was put off after Russia’s annexation of Crimea, an act condemned by members of the international community including Japan. The rescheduling of Putin’s visit has yet to be decided.

On Thursday, a close aide to Putin met with Abe in Tokyo and delivered a message from the Russian president, a senior Japanese official said, without revealing the substance of the text.

But Abe and Sergey Naryshkin, chairman of the Russian State Duma, did not discuss a visit to Japan by Putin, Chief Cabinet Secretary Yoshihide Suga told a news conference.

Asked whether Abe and Naryshkin discussed bilateral negotiations for the return of four Russian-held and Japan-claimed islands off Hokkaido, Suga declined to comment on the content of the 15-minute talks at a Tokyo hotel.

In a meeting Wednesday with Masahiko Komura, vice president of the ruling Liberal Democratic Party, Naryshkin said Japan’s imposition of sanctions on Russia over the Ukraine crisis was making it difficult to realize Putin’s visit to Tokyo.