Western allies are increasing economic pressure on Iran's energy sector and Central Bank, which would limit its ability to deliver crude oil to international consumers. Iran is one of the top oil producers in the Organization of the Petroleum Exporting Countries, though its influence is diminished because of concerns about its nuclear program.
Japanese Foreign Minister Koichiro Gemba said he had a "frank discussion" with U.S. Secretary of State Hillary Clinton, noting pressure on Iran's Central Bank might have negative consequences.
"I conveyed my view that there is a danger of causing damage to the entire global economy if the imports of Iranian crude oil stop," he said through an interpreter during a news conference.
Iranian Oil Minister Rostam Qasemi said last week that Iran considers the current market condition good in terms of oil prices. He added it was unlikely that markets would be further constrained because the European Union "definitely" won't sanction Iran's oil in response to nuclear weapon concerns.