International pressure was building up on Iran to respond positively to the six-nation proposals as the 35-nation board meeting of the International Atomic Energy agency (IAEA) began a debate on the country's nuclear issue yesterday.

The United States and the European Union (EU) urged Iran to accept the proposals which were presented to Tehran last week by EU foreign policy chief Javier Solana in exchange for the country's suspension of uranium enrichment.

U.S. chief delegate Gregory L. Schulte said in a statement that Iran had been resisting cooperation with the UN nuclear watchdog "on almost every outstanding issue."

He warned that refusing the six-power proposals could bring Iran to bear "the weight of the Security Council."

Schulte told reporters outside the meeting that there was wide agreement among the IAEA board of governors that Iran must cooperate now.

"With few exceptions, countries on the board... call on Iran to cooperate with the IAEA and create the conditions necessary for a comprehensive settlement," he said.

The European Union also urged Iran to cooperate as soon as possible.

In a statement, the EU said the six-nation offer was a "cooperative approach... a balanced approach" and urged "Iran to respond positively to this far-reaching initiative."

"International concerns about Iran's nuclear program remain to be resolved and that repeated requests by the board remain to be fulfilled," it said.

Francois-Xavier Deniau, France's chief delegate to the board meeting, said in a separate statement that "cooperation with the agency has been reduced to almost nothing these last few months and... numerous important questions remain to be resolved."

Meanwhile, China has urged Iran to "adopt a constructive attitude" and create favorable conditions for the restoration of talks at an early date.

China hopes the proposals "can serve as a basis for all sides to rapidly restore negotiations and provide conditions for resolving differences through negotiations," said Tang Guoqiang, the Chinese ambassador to the Vienna Office of the United Nations.

Russian President Vladimir Putin said in Shanghai, China after meeting Iranian President Mahmoud Ahmadinejad on the sidelines of the Shanghai Cooperation Organization (SCO) meeting, that Iran was ready to enter into the negotiations on the package.

Putin hoped Iran would set a date for the start of the talks.

On Thursday, Ahmadinejad avoided direct mention of the nuclear standoff with the West. But Iran's supreme leader Ayatollah Ali Khamenei said his country would not bow to pressure over its atomic program, implicitly rejecting international calls to suspend the uranium enrichment activities.

At the IAEA meeting, Iran's chief representative Ali Ashgar Soltanieh pledged to study the six-power proposals, which he said contained some "positive elements" and some "ambiguities."

Soltanieh warned against using threatening language in trying to persuade Tehran to cooperate.

Iran's right to uranium enrichment is not negotiable and Iran was ready to negotiate "without any precondition," he said in a statement.

The six powers have urged Iran to respond before mid-July, when the G8 summit is held.

Diplomats say China, Russia and possibly Germany might push to allow Iran some closely monitored and small-scale enrichment.

During the IAEA meeting, the 16 Non-Aligned board members also issued a statement that all nations have a "basic and inalienable right" to develop, produce and use atomic energy.