TEHRAN: President Mahmoud Ahmadinejad said Monday Iran will neither halt uranium enrichment nor negotiate over its nuclear rights but is ready to sit and talk with world powers over "global challenges."

His statements came as the U.N.'s nuclear watchdog warned of a "stalemate" over Iran's nuclear program. Members of the International Atomic Energy Agency began meetings in Vienna that could set the stage for a toughening of sanctions against Iran.

Ahmadinejad also said Iran will present a package of proposals for talks to the five permanent members of the U.N. Security Council plus Germany but rejected any deadline for such talks.

He said the package would "identify challenges facing humanity ... and resolve global concerns."

But he said that "from our point of view, Iran's nuclear issue is over. We continue our work within the framework of global regulations and in close interaction with the International Atomic Energy Agency." But "we will never negotiate over obvious rights of the Iranian nation," he said.

He said the only two aspects of the nuclear file he was willing to discuss were "creating peaceful nuclear energy for all countries" and a mechanism to prevent proliferation of nuclear weapons and encourage global nuclear disarmament.

President Barack Obama and European allies have given Iran until the end of September to take up an offer of nuclear talks with six world powers and trade incentives should it suspend uranium enrichment activities. If not, Iran could face harsher punitive sanctions.

The U.S. and some of its allies accuse Iran of using its civilian nuclear program as a cover to develop weapons. Iran has denied the charges, saying its nuclear program is aimed at generating electricity.

Iran has repeatedly vowed it will never suspend enrichment work, saying it has every right under the Nuclear Nonproliferation Treaty to enrich uranium and produce nuclear fuel. The enrichment process can produce either fuel for a reactor or the material for a warhead.

"It is very clear that this (deadline) is incompatible with the Iranian nation's needs and direction today," Ahmadinejad told a press conference Monday. "Resolving global issues requires constructive interaction on the basis of justice and respect."

Ahmadinejad said Iran will continue to cooperate with the IAEA over regulations on safeguards on its nuclear sites, "but we will resist if the agency is influenced by political pressures."

The agency's chief Mohamed ElBaradei, however, said Monday that the situation over Iran's nuclear program has reached a "stalemate."

He said Iran has not suspended uranium enrichment and not cleared up other lingering questions about possible military dimensions of its atomic activities, and he urged Tehran to "substantively re-engage" with the IAEA.

Iran says allegations of nuclear weapons studies by Tehran is based on forged documents but the U.S. and its European allies want to draw Iran back into negotiations over such concerns.

"The proposals we have prepared seeks to identify challenges facing humanity and basic directions for a durable solution to those challenges ... we are ready, within a logical and just framework, to sit and talk with all those ... who can make contribution to reform global affairs," Ahmadinejad told reporters.

The five permanent members of the U.N. Security Council — the U.S., France, Britain, Russia and China — plus Germany offered Iran a modified package of economic incentives June last year in return for suspending its uranium enrichment activities or face harsher sanctions.

Iran has said the incentives package has some "common ground" with Tehran's own proposals for a resolution to the standoff.

Germany and France — both important trade partners with Iran — have recently become far more forceful in their threats of possible sanctions.

Ahmadinejad did not directly address Obama's calls for a U.S.-Iran dialogue, and instead renewed an offer he has made in the past to hold a public debate with the U.S. president.

"Once again, I announce that I'm ready for debate and dialogue in front of global media on global issues," he said.

Meanwhile, Ahmadinejad nominated two hard-liners — including a woman — for two Cabinet posts after the parliament rejected his earlier nominees for the posts.

Fatemeh Alia, a conservative female lawmaker, was named for the post of education minister and hard-liner Ali Zabihi for the post of welfare and social security minister, state TV said. The president is expected to name a third nominee for the post of energy ministry.

Last week, parliament rejected three of Ahamdinejad's nominations for his 21-member Cabinet because they were considered unqualified for the posts.