World powers urged Iran to cooperate with the United Nations atomic watchdog at a meeting here Wednesday, where Iran once again found itself in the hot seat over its controversial nuclear drive.

"We call on
Iran to cooperate fully with the [International Atomic Energy] Agency," the so-called P5+1 grouping said in their first joint statement to the IAEA's board of governors in two years.

The P5+1 comprises the five permanent members of the U.N. Security Council--the U.K., China, France, Russia, the U.S.--plus Germany and is talking with the Islamic republic to allay fears over its nuclear program, which Iran insists is peaceful, but which the West believes masks a covert weapons program.

The last time the six powers issued a joint statement to the IAEA's 35-member board of governors was in March 2009.

Since then, the group has held two rounds of talks with
Iran , in Geneva in December and in Istanbul in January, but which produced no concrete breakthrough in the long-running standoff.

"We came to Geneva and Istanbul with a constructive spirit and proposed in Istanbul several practical ideas aimed at building confidence and to facilitate the engagement of a constructive dialogue with Iran on the basis of reciprocity and step-by-step approach," said Russian governor Grigory Berdennikov on behalf of the P5+1.

While no "substantive result" was reached in
Istanbul , "we look to Iran to engage in future in a similarly constructive spirit," Berdennikov said.

"We remain ready to participate actively in the process with
Iran . We expect Iran to demonstrate a pragmatic attitude and to respond positively to our proposal and to our openness toward dialogue and negotiations. The door remains open," he said.