Azumi, right, said Japan planned to take "concrete steps" to reduce its useage of Iranian oil [Reuters]

Japan has pledged to reduce import of Iranian oil as part of US-led efforts to put pressure on the Middle East nation to end its nuclear programme.

Jun Azumi, the Japanese finance minister, speaking on Thursday after meeting with Timothy Geithner, his US counterpart, in Tokyo, said that Iran's "nuclear development problem" could not be ignored and said it understood US actions.

"In the past five years, we have reduced... the amount of oil imported (from Iran)," he said. "We wish to take planned and concrete steps to further reduce this share, which now stands at 10 percent."

Japan's move is a boost for Geithner, the US treasury secretary, who earlier in his trip failed to persuade China to back US efforts  to strangle the Iranian oil industry .

The decision comes with Japan already coping with reduced energy supplies with most of its 54 nuclear power plants offline because of routine maintenance work in the wake of last March's nuclear crisis at the Fukushima plant.

Experts however, said the move would have limited negative impact on Japan's economy as the country would probably be able to offset any reductions by increasing imports from other major oil producers such as Saudi Arabia and the United Arab Emirates.

The US treasury secretary said: "We very much appreciate the support Japan has provided in standing with us and the international community in support of this very important strategic objective."

He said that the US was working closely with "countries around the world to substantially increase the amount of pressure we bring on Iran" by cutting off "the central bank from the international financial system and to reduce the earnings Iran derives from its oil exports".

The European Union also looks set to join the US embargo on Iranian oil exports with Denmark, which holds the EU presidency, expressing confidence on Wednesday that European sanctions would be finalised later this month.

Europe is collectively the second-biggest destination for Iranian oil exports after China, taking in some 450,000 barrels per day, and the countries most dependent on Iranian oil, including Greece, Italy and Spain, want to delay the start of the sanctions while they search for other sources.

Iran has threatened to respond to sanctions by shutting the Strait of Hormuz, a transit route for a fifth of the world's oil.