MOSCOW — Russia has made its first shipment of nuclear fuel to an Iranian nuclear power plant at the center of the international tensions over Tehran’s atomic program, the Foreign Ministry said today.

America said the Russian delivery gave Iran another reason to suspend its enrichment program.

America has been unhappy about Russia helping Iran build the Bushehr nuclear plant. But President Bush has supported Russia in providing uranium fuel to Iran — but only if Moscow retrieves the used reactor fuel for reprocessing.

Iran contends the plant is strictly for civilian purposes, but critics say it could be used to advance efforts to build nuclear weapons.

The construction of the Bushehr plant has been frequently delayed. Officials said the delays were due to payment disputes, but many observers suggested Russia also was unhappy with Iran’s resistance to international pressure to make its nuclear program more open and to assure the international community that it was not developing nuclear arms.

Russia announced last week that its construction disputes with Iran had been resolved and said fuel deliveries would begin about six months before Bushehr was expected to go into service.

“All fuel that will be delivered will be under the control and guarantees of the International Atomic Energy Agency for the whole time it stays on Iranian territory,” the Foreign Ministry said in a statement. “Moreover, the Iranian side gave additional written guarantees that the fuel will be used only for the Bushehr nuclear power plant.”

Iran confirmed that it had received the shipment, the official Iranian news agency IRNA reported.

“The first nuclear fuel shipment for the Bushehr atomic power plant arrived in Iran Monday,” IRNA quoted the Iranian vice president, Gholam Reza Aghazadeh, as saying.

The 2005 agreement under which Russia agreed to supply nuclear fuel for Bushehr included a clause that requires Iran to return the spent fuel to prevent any possibility Tehran would extract plutonium from it to make atomic weapons.

Mr. Aghazadeh said the Bushehr plant was 95% complete and would begin operations “next year.” He indicated the reactor needed 80 tons of nuclear fuel during the initial phase of operation, but did not provide further details.

America has been pushing the U.N. Security Council to pass a third round of sanctions against Iran for its refusal to suspend uranium enrichment.

“This fuel shipment gives the Iranians one more reason to suspend their enrichment program,” a White House spokesman, Gordon Johndroe, said. “If they’re getting fuels from the Russians now, Iran doesn’t need its own program.”

A White House spokeswoman, Dana Perino, noted the Russian said the IAEA “will be involved in this transaction. So that is a step — I would say a good step in that direction.”

The American effort became more difficult earlier this month with the release of a new American intelligence report that concluded Iran had halted its nuclear weapons development program in 2003 and had not resumed it through at least the middle of this year.

Although Russia has resisted drives to impose sanctions on Iran, it also repeatedly has urged Tehran to cooperate with the Vienna, Austria-based IAEA to resolve concerns over the nuclear program.

Foreign Minister Sergey Lavrov underlined that position last week after a meeting in Moscow with his Iranian counterpart, Manouchehr Mottaki.

Mr. Lavrov said resolving the controversy is possible “solely on the basis of the nuclear nonproliferation treaty, IAEA rules, and principles and, certainly, with Iran proving its right to the peaceful use of nuclear energy.”

Officials at Atomstroyexport, the Russian contractor for Bushehr, raised the prospect last week of creating a Russian-Iranian joint venture “to ensure security” at the Bushehr plant, according to the RIA-Novosti agency.

That could indicate Russian interest in ensuring that enriched uranium at the plant is not stolen or diverted. Depleted fuel rods also could be reprocessed into plutonium.