National security adviser H.R. McMaster said President Trump doesn't trust the Iranians to comply with the terms of the Iran nuclear deal and it's time for stricter enforcement with a parallel agreement.

McMaster said on "Fox News Sunday" Trump's speech on Friday decertifying Iran's compliance with the deal was "a marker" announcing "we have to fix the fundamental flaws in this deal."

"It's a weak deal that is being weakly monitored," he said.

McMaster said Trump's tough stance on the deal is already having an impact on how other countries are treating the Iran deal.

"They already are revisiting the terms of the deal and implementation. Our European allies — France, Germany and the U.K. — are supporting much more rigorous enforcement of the [Joint Comprehensive Plan of Action] and monitoring," he said."

"One of the real problems with this deal is we can't really say with confidence that they are complying and we know from their behavior, their behavior broadly in the region and their behavior within the agreement where they have walked up to the line, they have crossed the line several times."

When asked why Iran would revisit the deal at Trump's request, McMaster dodged and simply said, "They have to revisit it."

"They have to revisit it because otherwise what you do is you give the Iranians the opportunity to develop the nuclear capability," he said. "Their programs can advance and then they can go to industrial scale enrichment of uranium within a very short period of time and bridge into a weapon and that is just an unacceptable risk to the world."