The government on Friday welcomed a decision by the Organization of Petroleum Exporting Countries to raise its output ceiling by 2 million barrels a day in July in a bid to bring down record crude oil prices.
"I very much respect the overall decision by OPEC," Shoichi Nakagawa, minister of economy, trade and industry, told a news conference.
OPEC agreed at a meeting Thursday in Beirut to raise the target by an additional 500,000 barrels a day in August if necessary.
Finance Minister Sadakazu Tanigaki told a separate news conference that he welcomes OPEC's decision, adding that the government wants to see the decision take effect.
But the ministers remained concerned because oil prices have been pinned around $40 a barrel for the past three weeks, fueled by solid world economic growth and fears over supply security in the Middle East.
U.S. benchmark crude oil futures hit a new high of $42.38 Tuesday, following a terrorist attack on foreign oil workers over the weekend in Saudi Arabia that left 22 people dead.
Tanigaki said current crude oil price levels are "by no means welcome" for the world economy, especially for developing countries, citing the importance of curbing speculative moves in crude oil markets.
"We must closely monitor developments in oil prices, including moves linked to future OPEC decisions about output in the future," he said.
Nakagawa said the government will carefully watch price developments in Japan, such as possible increases in gas prices.