Iranian Oil Minister Rostam Qasemi speaks with the media in a news conference in Tehran on Saturday. (Vahid Salemi/Associated Press)

Iran’s oil ministry said Sunday that it has cut off oil exports to France and Britain in what officials described as the first in a series of punitive measures targeting “hostile” European countries for supporting economic sanctions against the Islamic republic.

The mostly symbolic move appeared aimed at blunting the political impact within Iran of a European oil embargo set to begin in the summer. Iranian officials have sought to play down the loss of the country’s European customers, who collectively consume about 18 percent of Iran’s petroleum exports.

“Crude oil exports to British and French companies have been halted,” Ali Reza Nikzad-Rahbar, a spokesman for Iran’s Oil Ministry, said in a statement on the agency’s Web site. The official added that Iran had other customers and would “have no problem to sell and export our crude oil.”

The impact of the move is likely to be minimal, as Britain imports no oil from Iran, while France is already on track to phase out Iranian crude, which currently makes up less than 4 percent of the country’s oil imports.

Iran’s announcement comes four days after state-run news media reported that Iranian officials were planning to terminate oil contracts with up to six European countries in retaliation for sanctions. Government spokesmen later denied the reports, but not before global oil prices shot up to an eight-month high as investors fretted about shortages and escalating prices.

The wrangling over oil comes as Western nations prepare to further increase the economic and political pressure to force Iran to give up its nuclear ambitions. In addition to the oil embargo, European Union nations are moving to exclude Iranian banks from the international financial messaging system known as Swift, a move that will make it harder for Iran to collect money from its foreign oil sales.

Despite stiff sanctions, Iran has refused to agree to curbs on its nuclear program, which it says is intended only for generating electricity. Western governments contend that Iran is moving systematically toward a nuclear weapons capability under the cover of a civilian nuclear energy program.

But Iran has also hinted that it might be open to making concessions. Iranian officials last week sent a letter to E.U. officials expressing willingness to resume international talks on its nuclear program. Western governments cautiously welcomed the proposal, which could lead to the first direct talks in more than a year. Iran agreed to host a special visit by a delegation from the International Atomic Energy Agency, which traveled to Tehran on Sunday for what the U.N. agency hoped would be a detailed discussion of Iran’s past nuclear activities.

The Obama administration, meanwhile, continued to play down talk about possible preemptive military strikes against Iranian nuclear facilities. The White House dispatched National Security Adviser Thomas E. Donilon to Israel over the weekend, the latest in a series of high-level visits focused primarily on Iran and the worsening crisis in Syria. Donilon was scheduled to meet with Prime Minister Benjamin Netanyahu and other senior Israeli officials.

Hours before the talks began, the top U.S. military officer repeated the administration’s view that a unilateral Israeli strike against Iran would be “not prudent.”

“That’s been our counsel to our allies, the Israelis, well known and well documented,” Gen. Martin Dempsey, chairman of the Joint Chiefs of Staff, said on CNN’s Sunday news show “Fareed Zakaria GPS.”

The Associated Press contributed to this report.