J.D. Vance, an opponent of the Iran nuclear deal and a candidate endorsed by former president Donald Trump has won the Republican Senate nomination in Ohio.

Vance gained an advantage in mid-April in a crowded field of candidates, when Trump endorsed him and propelled him to the top spot, in a sign of the former president’s political fortunes in upcoming primaries in other states.

In the run up to the primary vote, Vance criticized President Joe Biden’s“obsession with re-entering the disastrous Obama Iran deal,” and said, “One of the President Trump's best foreign policy decisions was getting out of that deal, and we need to fight Biden hard on this.“

Entering indirect talks with Iran to revive the 2015 nuclear agreement, known as JCPOA, was one of the first foreign policy initiatives of the Biden administration. After 13 months of talks an agreement remains elusive as Iran demands the removal of its Revolutionary Guard from the US list of terrorist organizations.

Opoosition to the talks and to the revivial of the JCPOA have increased in the past two months, with almost all Republicans in the Senate and some Democrats telling the administration not to make concessions to Tehran.

Vance will battle Democratic Rep, Tim Ryan in the November elections, who easily won his party’s primary, but will face a difficult fight in Republican-leaning Ohio.