Japan expects a limited impact from the U.S. decision not to renew waivers previously granted on Iran oil import sanctions, the country's trade and industry minister said Tuesday.

The United States on Monday demanded all buyers of Iranian oil stop purchases by May 1 or face sanctions, a move to choke off Tehran's oil revenues that sent benchmark crude prices to six-month highs. Japan is among a group of countries that were previously granted sanctions waivers.

Hiroshige Seko, head of the Ministry of Economy, Trade and Industry (METI), told reporters the government does not see any need to tap national oil reserves following the U.S. decision.