More than a dozen US senators, in a letter to the US envoy to the United Nations, Nikki Haley, expressed concern over what they called “shortcomings” in the UN nuclear agency’s inspection regime and demanded stricter supervision of Iran’s nuclear activities. The senators’ letter appeared to boost an attempt to appease the administration of US President Donald Trump who is seeking to impose a more stringent monitoring regime that would include access to Iran’s military facilities, something that officials in Tehran have flatly rejected. “We write to you to express concern regarding shortcomings in the inspection and verification regime of the United Nations nuclear watchdog, the International Atomic Energy Agency, regarding the Joint Comprehensive Plan of Action,” said the letter, signed by 13 US lawmakers and carried on the website of one of the signatories, David Perdue. They were using the formal title of a landmark agreement Iran sealed with the six major powers in July 2015 to receive sanctions relief in return for temporary curbs on its nuclear work. The action plan has tasked IAEA with monitoring Iran’s compliance with the deal’s provisions. “We are confident that together we can bolster the inspection and verification regime of JCPOA to ensure that the deal is fully and verifiably enforced,” the letter said.