Japan has asked Saudi Arabia and the United Arab Emirates (UAE) to supply it with more oil, Japanese Foreign Minister Koichiro Gemba said on Tuesday, as tighter Western sanctions threaten to reduce its oil imports from Iran.

Japan is considering cutting its Iranian oil purchases to secure a waiver from the new U.S. sanctions on the Islamic Republic over its disputed nuclear programme.

Foreign minister Gemba has been on a visit to Turkey and Gulf Arab countries since last week in what some analysts said could be a sign that Tokyo is seeking assurances from Gulf producers that they would compensate for any potential loss of Iranian oil.

"We want an increase in the quantity of oil that Japan needs (from these countries)," Gemba, speaking through an interpreter, said at a joint news conference in Abu Dhabi with United Arab Emirates Foreign Minister Sheikh Abdullah bin Zayed al-Nahayan.

A spokesman for the Japanese foreign ministry, Masaru Sato, declined to discuss the quantities of extra oil sought by Japan but said a team of technical experts was to travel to Saudi Arabia and the UAE to discuss the details.

Sheikh Abdullah said the UAE, a major oil exporter, has the capacity to produce extra oil and is ready to give priority to Japan, one of the Gulf Arab state's main trading partners with some $35 billion.

"Part of developing this relationship is to provide energy to Japan. The UAE has the capacity to provide more energy. The UAE has taken this request in a positive way.

Tensions in the Strait of Hormuz - the world's most important oil shipping lane - have risen in recent weeks after Iran threatened to block the narrow strip of water, through which producers Saudi Arabia, Iran, Iraq and the UAE rely to supply customers around the world.

Japan, which depends on energy imports, is one of the biggest buyers of oil produced in the Gulf.

The West is considering imposing sanctions on Iranian oil exports over its disputed nuclear program, prompting Iran's threat to close the Strait if its oil exports are disrupted.

Gemba urged Tehran to refrain from any what he described as "provocative" action.

"Iran must not threaten the safety of Strait of Hormuz," Gemba said. "Japan is concerned about the situation."

Japan imports around 25 per cent of its oil from the UAE, 30 per cent from top oil exporter Saudi Arabia and around 10 per cent from Qatar, another producer entirely dependent on the Strait of Hormuz to ship its crude exports.

OPEC member UAE pumped around 2.6 million barrels per day (bpd) in December, leaving it with a spare capacity of around 100,000 bpd.

Sheikh Abdullah also said protecting energy export routes was an international responsibility and that it was in Iran's interests, as well as Gulf Arab oil exporters, to maintain oil market stability.

"We have heard varying comments from Iran. At first, we heard statements about closing the Strait (of Hormuz), but we also heard denials. I hope this language (of reason) prevails," he said.