China agrees with the U.S. that Iran must prove its nuclear program is of a peaceful nature and not aimed at producing an atomic bomb, U.S. President Barack Obama said in Beijing on Tuesday.

"We agreed that the Islamic Republic of Iran must provide assurance to the international community that its nuclear program is peaceful and transparent," Obama said, speaking at a joint news conference with Chinese leader Hu Jintao.

"Iran has an opportunity to present and demonstrate its peaceful intentions, but if it fails to take advantage of this opportunity it will face consequences" he added.

Western powers believe that Iran is attempting to build nuclear weapons. Tehran maintains it is only interested in the peaceful generation of power. Top Iranian presidential adviser Parviz Davoudi said on Monday that Tehran could agree to a UN-brokered deal to send its uranium for processing in Europe if it receives enriched uranium for its research reactor first.

The two leaders also said that they agreed that negotiations were the best way to deal with North Korea's controversial nuclear program.

Hu also told reporters that China welcomed the U.S.'s recommitment to its one-China policy.

His comments came after Obama said on Monday that Washington "supports a one-China policy."

"We don't want to change that policy or approach," Obama said. "Through dialogue and communications problems can be solved."

The U.S. president refused however to answer a question on U.S. arms supplies to Taiwan, which split from mainland China in 1949.