The head of the United Nations agency that monitors Iran's compliance with an international nuclear deal says Tehran is honoring the agreement with six world powers.
Yukiya Amano, the director-general of the International Atomic Energy Agency (IAEA), said at the start of an IAEA board meeting in Vienna on September 11 that the terms Iran accepted "are being implemented."
However, the assessment is being questioned by Washington as President Donald Trump's administration considers whether to increase pressure on Iran.
Since Trump took office in January, the United States has faced two 90-day certification deadlines to state whether Iran was meeting the conditions needed to continue enjoying sanctions relief under the deal.
Both times, Washington has backed away from declaring Iran not in compliance with its obligations.
But Trump recently said he did not expect to certify Iran's compliance again.
The next deadline for U.S. certification is in mid-October.
Meanwhile, Amano also said at the September 11 IAEA meeting that North Korea's "continuation and further development" of nuclear weapons was "a cause of grave concern."
He urged Pyongyang to resume cooperation with the UN nuclear watchdog, whose nuclear inspectors were kicked out of North Korea in 2009.
North Korea threatened to cause the United States "the greatest pain and suffering it had ever gone through in its entire history" ahead of a UN Security Council meeting called by Washington to consider new sanctions against Pyongyang.
North Korea's Foreign Ministry said on September 11 that the country was "ready and willing to use any form of ultimate means" against the United States.
The draft resolution for tougher UN sanctions includes a proposal to cut off foreign oil supplies to North Korea.