Bushehr, Iran ? Iran and Russia ignored U.S. objections and signed a nuclear fuel agreement Sunday that is key to bringing Tehran’s first reactor online by mid-2006.

The long-delayed deal, signed at the heavily guarded Bushehr nuclear facility in southern Iran, dramatized President Bush’s failure to persuade the Russians to curtail support for the Iranian nuclear program during his summit with Vladimir Putin Thursday in Slovakia.

Under the deal, Russia will provide nuclear fuel to Iran, then take back the spent fuel, a step meant as a safeguard to ensure it cannot be diverted into a weapons program. Iran also has agreed to allow the U.N. nuclear watchdog agency, the International Atomic Energy Agency, to monitor Bushehr and the fuel deliveries.

Iranian Vice President Gholamreza Aghazadeh and Russian Federal Atomic Energy Agency chief Alexander Rumyantsev signed the agreement. The signing, which was delayed by a day, came after the two senior officials toured the $800 million complex.

Both officials refused to discuss the details of shipping the nuclear fuel to Iran and the spent fuel back to Russia, but they insisted that the agreement conforms to international nuclear regulations.

“Iran observes all the regulations on the prohibition of the spread of nuclear weapons,” Rumyantsev said.

The White House declined comment, as did the State Department.

Two Iranian security officers stand guard at the gate of the Bushehr nuclear power plant in Iran. Iran and Russia signed a nuclear fuel agreement Sunday, paving the way for Iran to get its first reactor up and running.

Washington accuses Tehran of covertly trying to build a nuclear bomb, which Iran denies. Thursday’s summit between Bush and Putin in Bratislava, Slovakia, had touched on American concerns over Russian support for Iran’s nuclear program.

Putin has said he is sure Iran’s intentions are merely to generate energy, not create weapons, and that Russian cooperation with Tehran would continue.