The United States has given up on trying to deny ElBaradei, who has headed the International Atomic Energy Agency since 1997, a third term as it has no backing from among the body's 35-nation board of governors, diplomats said.

The board will choose a new head when it meets at IAEA's headquarters in Vienna next week. ElBaradei is the only candidate for the director general post.

ElBaradei had provoked the ire of Washington for questioning US intelligence that Iraq had weapons of mass destruction under now deposed dictator Saddam Hussein and for not being tough enough on Iran, which Washington charges is hiding a covert nuclear weapons program, diplomats said.

But the United States is now "willing to lift our objections under certain conditions. Namely, get tougher on Iran," a US official told the Washington Post on Tuesday.

ElBaradei, 62, is due to meet Thursday in Washington with Rice and also with the new US undersecretary for non-proliferation, Robert Joseph, and the new US Secretary of Energy Samuel Bodman, IAEA spokesman Mark Gwozdecky said.

ElBaradei has said the "jury is still out" on whether Iran is secretly developing nuclear weapons, even if IAEA inspectors have discovered that Iran hid sensitive atomic work for almost two decades until the agency's inspection of the Iranian program began in 2003.

The main question now, said diplomats, is what conditions the United States will put on ElBaradei's getting a third term.

"There are limits to what ElBaradei is going to do for the United States. The United States is in a weak position (on the IAEA board). But it is still in the interests of ElBaradei to get US support," the European diplomat said.

The United States, for instance, wants help for tougher enforcement of international nuclear safeguards and is proposing at next week's board meeting the creation of a special committee to crack down on violations of the nuclear Non-Proliferation Treaty (NPT) in countries such as Iran, according to a confidential IAEA document obtained by AFP.

ElBaradei is now backing this text, which has been "thoroughly rewritten" in recent months, a Western diplomat close to the IAEA said.

The diplomat said said one key change was to leave it "open-ended" as to who would serve on the committee instead of excluding countries which are under investigation, such as Iran. Iran was last year on the IAEA board.

Another concession which ElBaradei has made is to promise a full report on Iran at next week's board meeting. The report will be made by deputy director for safeguards Pierre Goldschmidt.

The report comes at a time when the European Union is trying to work out a deal with Iran to provide guarantees it is not making nuclear weapons and diplomats have said the Europeans want to take a "minimalist approach" at this board meeting, avoiding a finger-pointing report that could alienate the Iranians.

"The sheer fact that there will be a report is interesting," one diplomat said, adding that ElBaradei had changed his mind on this "under US pressure."

Diplomats said however that the US position has become less confrontational towards the IAEA since Joseph was appointed on Friday the State Department's new undersecretary for non-proliferation.

Joseph replaced the hawkish John Bolton who is currently fighting to get Congressional approval to become US ambassador to the United Nations.

Rice has stressed the importance of diplomacy since she took office.

"If the United States is going to support ElBaradei this is going to have a positive effect on the whole climate" at the IAEA, a European diplomat said.