By Fredrik Dahl
VIENNA (Reuters) - World powers told Iran on Wednesday "the door remains open" for dialogue on its disputed nuclear program, and that Tehran must cooperate with the U.N atomic watchdog to resolve concerns it may have military aims.
The six powers issued a rare joint statement at a meeting of the International Atomic Energy Agency (IAEA), in a bid to show unity and to step up pressure on Iran after their talks with the Islamic state in December and January failed to make progress.
It was issued after IAEA Director General Yukiya Amano on Monday, the first day of a meeting of the agency's board, said information his office recently received added to concerns about possible military aspects to Iran's atomic activities.
Amano voiced growing frustration at what the Vienna-based body sees as Iran's failure to address allegations it may be working to develop a nuclear-armed missile.
The statement from the United States, Russia, Britain, France, Germany and China said: "We call on Iran to cooperate fully with the Agency ... Outstanding issues need to be resolved in order to exclude the existence of possible military dimensions to Iran's nuclear program."
It was the first joint statement by the big powers at the IAEA since March 2009.
Iran denies Western accusations it is seeking nuclear weapons capability, saying its atomic activities are aimed at generating electricity so it can export more of its oil and gas.
NUCLEAR WARHEAD WORK?
For several years, the IAEA has been investigating Western intelligence reports indicating Iran has coordinated efforts to process uranium, test explosives at high altitude and revamp a ballistic missile cone so that it can take a nuclear warhead.
Iran, one of the world's biggest oil producers, says the allegations are based on forged documents.
The powers' statement said two rounds of talks with Iran in Geneva in December and in Istanbul in January did not reach any substantive result, despite their "constructive spirit" and practical ideas aimed at building confidence.
"We expect Iran to demonstrate a pragmatic attitude and to respond positively to our proposals and to our openness toward dialogue and negotiations," the statement, read out by Russian Ambassador Grigory Berdennikov at the closed-door meeting of the IAEA's 35-nation governing board, said.
"The door remains open," the statement said.
The U.S. envoy to the IAEA, Ambassador Glyn Davies, made a separate statement to the board, about the "increasingly apparent military dimensions to Iran's nuclear program, including efforts by Iran to develop a nuclear warhead."
He urged Amano to report "promptly to the board his best assessment of whether there have been military dimensions to nuclear activities in Iran and, if so, whether he is in a position to verify they have stopped."
The U.N. Security Council has imposed four rounds of sanctions on Tehran since 2006 for refusing to freeze its uranium enrichment program, which can have both civilian and military purposes.
(Editing by Louise Ireland)