The Japanese government on Friday appeared split over a pledge to cut oil imports from Iran, just a day after the finance minister told his US counterpart it would do what Washington wanted.
The US is trying to raise pressure on Iran over its nuclear programme, threatening to cut off financial institutions that deal with the country's central bank, so squeezing Tehran's vital oil export business.
China had refused to play ball, but Washington appeared to have scored a diplomatic victory during a visit by Treasury Secretary Timothy Geithner on Thursday when Jun Azumi said Tokyo was planning to cut its imports from Iran.
But on Friday his colleague, Foreign Minister Koichiro Gemba, said no decision had been taken.
"I understand it was Mr Azumi's view on the current state and outlook (of Japan's oil imports)," Gemba was quoted as saying by the Nikkei business daily.
"If crude oil prices surge (as countries seek other suppliers), it would rather benefit Iran. It could invite consequences that go counter to the original purpose of the sanctions," Gemba reportedly said.
Kyodo news agency also quoted Gemba describing Azumi's comments as a "forecast".
Azumi insisted Friday that there was "no confusion" and "no inconsistency" within the government, Kyodo reported.
The apparent difference of opinion co-incided with a cabinet reshuffle by Prime Minister Yoshihiko Noda, in which both men kept their jobs.
Resource-poor Japan is heavily dependent on Middle East oil and has maintained relations with Iran in the face of pressure to ostracise the country