Washington Examiner | Joel Gehrke : President Trump's new Iran strategy will succeed or fail based on the ability of his administration to rally European support, according to a top Senate Republican.

"I think before it's all over with, it's going to be easy if the administration does its job on the diplomatic effort with our allies," Senate Foreign Relations Chairman Bob Corker, R-Tenn., told the�Washington Examiner�on Tuesday. "They do their work there, this is very easily done."

That statement puts the onus back on the administration, after Trump threatened to scrap the Iran nuclear deal unilaterally if Congress and European allies can't make headway on a plan to curb the regime's behavior. Corker is one of the top Republicans working on legislation to implement what Trump calls "phase two" of his new Iran strategy.

The term refers to the period between his announcement that the deal as written is not in U.S. interests and the renewal of economic sanctions waived under the pact. Trump has said repeatedly that he hopes the threat of sanctions will create an incentive to negotiate new restrictions on Iran.

"We'll see what phase two is," Trump said. "Phase two might be positive and it might be negative. It might be a total termination. That's a very real possibility, some would say that's a greater possibility, but it also could turn out to be very positive."

Corker, along with Arkansas Sen. Tom Cotton, is working on legislation that would require the president to impose sanctions if Iran's nuclear program advances to the point that the regime is less than a year away from getting a nuclear weapon. That legislation is subject to a filibuster, however, raising the possibility that Democrats could block the proposal and Trump withdraws the United States entirely from the deal.

"In the event we are not able to reach a solution working with Congress and our allies, then the agreement will be terminated," Trump said Friday. "It is under continuous review, and our participation can be cancelled by me, as president, at any time."

Corker hopes that a filibuster threat won't be on the table. "We're not going to attempt to do a 60-vote deal; we're trying to do an 80 vote deal," he said. "We're not saying, okay, these eight senators. Our effort is to have an overwhelming vote."

The top Democrat on the Foreign Relations Committee allowed that his party might back a proposal like Corker's, but avoided hinting at any concessions. "We're more than happy to give the president the strongest possible hand so Iran complies with the nuclear agreement and to deal with the non-nuclear violations," Maryland Sen. Ben Cardin told the�Washington Examiner. "We're not going to violate the [Iran deal] and we need European support."

In practice, according to Corker, European support means a willingness to match the United States' efforts to gain broader inspection authority and extend the lifetime restrictions on Iran's ballistic missiles and nuclear program. So far, European leaders have been critical of Trump's denunciation of the agreement.

"We are not discussing introducing further restrictions on Iran," Federica Mogherini, the European Union's top foreign policy official,�told reporters�Monday.

Corker predicted that will change, but only if Trump's team appeals to them effectively between now and January.

"My guess is that we're talking about something that occurs after the first of the year," he told reporters. "This is something that we're going to take our time to do and do it right and a big part of this being successful will be the administration's efforts diplomacy-wise with our European allies. That is something that has got to take place or many of our Democratic colleagues are not going to be willing come along."