WASHINGTON, Dec 24: The United States has warned all nations not to extend nuclear cooperation to Iran and urged Tehran to comply with its international obligations.

The warning, issued at a State Department briefing on Tuesday, followed media reports that Pakistani scientists had assisted Iran’s nuclear programme before October 1999.

“All nations should avoid nuclear cooperation with Iran, particularly in the areas of weapons development,” said State Department spokesman Richard Boucher.

“Iran needs to comply with all the requirements of the (IAEA) board of governors,” he added. The International Atomic Energy Agency, a Vienna-based organization that monitors nuclear proliferation for the United Nations, has urged Iran to immediately stop all activities for making nuclear weapons and open all nuclear installations for IAEA inspection.

Media reports in the United States have claimed that documents IAEA received from Iran point to a possible link between Iran and some nuclear scientists in Pakistan.