US Secretary of State John Kerry on Thursday briefed wary Gulf ministers about his latest nuclear talks with Iran.

US Secretary of State John Kerry on Thursday briefed wary Gulf ministers about his latest nuclear talks with Iran.

Fresh from three days of talks in Switzerland, Kerry gathered at a Riyadh air base with foreign ministers from the six Gulf Cooperation Council nations.

Their agenda is also expected to tackle the battle against Takfiris in Iraq and Syria.

Kerry arrived after talks with Iran's Foreign Minister Mohammad Javad Zarif, aiming to seal a nuclear deal with Tehran ahead of a March 31 deadline.

Kerry sought to allay fears over the deal between Teran and Washington, saying Washington remained concerned about Iran's bid to spread its influence in the region.

"For all the objections that any country has to Iranian activities in the region -- and believe me, we have objections and others in the world have objections -- the first step is to prevent Iran from acquiring a nuclear weapon," he told reporters Wednesday before leaving Switzerland.

"Even as we negotiate, this in no way represents a broader warming of ties, lessening of concerns on our part," said Deputy State Department spokeswoman Marie Harf.

"This is not about a broader rapprochement in any way. This is about the nuclear issue and that's it," she added.

The P5+1 group of Britain, China, France, Russia, the US and Germany is trying to strike an accord on Iran nuclear program.