The UN nuclear watchdog on Friday confirmed that Iran has been implementing the Iran nuclear deal under the robust nuclear verification regime.

International Atomic Energy Agency Director General Yukiya Amano said Tehran was cooperating with the agency to commit to the conditions of the deal.

Since January 2016, the IAEA has been verifying and monitoring Iran's implementation of its nuclear-related commitments under the Joint Comprehensive Plan of Action, as requested by the United Nations Security Council and authorized by the IAEA's board of governors, Amano said in a statement Friday.

The statement was issued after US President Donald Trump said he could not certify Iran's compliance because the country has committed "multiple violations" of the deal.

"As I have reported to the board of governors, the nuclear-related commitments undertaken by Iran under the JCPOA are being implemented," Amano said. "Iran is now provisionally implementing the Additional Protocol to its Comprehensive Safeguards Agreement with the IAEA, a powerful verification tool which gives our inspectors broader access to information and locations in Iran."

At present, Iran is subject to the world's most robust nuclear verification regime, he said in the statement.

Earlier reports said the IAEA had, on eight occasions in the past, certified Iran's compliance with the nuclear deal.