The head of the International Atomic Energy Agency warned Thursday that the “space for negotiation and diplomacy ... is getting smaller” over Iran's advancing atomic program as wars in the Mideast rage on and as President Donald Trump will return to the White House.

Rafael Grossi, head of the International Atomic Energy Agency, the U.N. nuclear watchdog, says the window of opportunity to diplomatically engage with Iran is beginning to "shrink."

U.N. atomic watchdog chief Rafael Grossi appealed to Iran's leadership on Tuesday to take steps to resolve longstanding issues with his agency a day before he arrives in the Iranian capital for crunch talks over its nuclear programme.

The head of the United Nations’ nuclear watchdog said Tuesday he's hopeful that meetings this week with Iranian officials, including the country's new president, can lead to a breakthrough in monitoring the country's nuclear program,

Foreign Minister Abbas Araghchi said Thursday that Iran will not negotiate under "intimidation" as he held crunch talks with the UN nuclear chief weeks before US President-elect Donald Trump takes