"I think we should enforce the hell out of the agreement and thereby force compliance on the part of Iran," Royce, a California Republican, said in an interview on CNN's "The Lead with Jake Tapper."
Royce's comments came hours after President Donald Trump addressed
the United Nations General Assembly and railed against the agreement between global powers and Iran concerning sanctions and the country's nuclear intentions.
"Frankly, that deal is an embarrassment to the United States, and I don't think you've heard the last of it -- believe me," Trump said. The President said Iran supports terrorists and destabilizes the region.
Despite campaigning against the agreement, Trump has continued
to keep it in place since taking office.
Secretary of State Rex Tillerson said in a CBS interview on Sunday
that Iran is in "technical compliance" with the deal, but claimed it is continuing destabilizing behavior and, therefore, going against the broader intention of the agreement.
Tillerson said on Fox News on Tuesday evening that the US would seek to alter Iran's behavior in the region either through a renegotiation of the nuclear agreement, or "in other ways."
Royce, in his CNN interview, said the right course was to focus on making sure Iran continued to hold up its end of the agreement, as well as pushing back on Iran throughout the region, particularly by keeping its forces away from Israel.
"Going forward, how do we focus on compliance and enforcement of the agreement?" Royce said. "And how do we focus on preventing them from moving forward with their intercontinental ballistic missile programs, as well as their movement of troops?"
Royce said he believed Iran was "violating the spirit of the agreement," but he said the lifting of sanctions under the Iran deal meant the US lost a considerable amount of leverage that went directly to the Iranian Revolutionary Guard Corps.
"They now have this money," Royce said. "And so in a way, the toothpaste is out of the tube."
He warned further about Iran's ballistic missile program, and in response to the threats he listed, he cited the sanctions legislation he supported earlier this year that Trump signed into law.