Japan is working closely with G7 nations to ensure effective economic sanctions against Russia and its central bank, its top currency diplomat said after a meeting of government and central bank executives to debate the fallout from the Ukraine crisis.

"We will respond, working closely with the international community including the G7 nations, so that we exert maximum cost to Russia" for invading Ukraine, Masato Kanda, vice finance minister for international affairs, told reporters on Monday.

Kanda, who oversees Japan's currency policy at the ministry of finance (MOF), made the remarks after the meeting with his counterparts at the Bank of Japan and the Financial Services Agency - the first such gathering in roughly a year.

Japanese shares fell and the yen drew demand as a safe haven currency on Monday, after Western nations imposed new sanctions on Russia for its invasion of Ukraine including blocking some banks from the SWIFT international payments system.

"We are adjusting (with Western economies) to ensure the sanctions are effective," Kanda said.

"Market stability is extremely important," he said, adding the government was closely watching market developments.

The trilateral meeting is typically held in times of market stress to communicate policymakers' views or concern over stock market or exchange rate volatility. The meeting was last held in January last year.