MONTREUX: US Secretary of State John Kerry is visiting Riyadh this week to reassure the newly appointed King Salman that any nuclear deal with Iran is in Saudi Arabia's interest.

The Saudi kingdom is critical of any deal between US and Iran, fearing it may boost support for Shia Muslims' interest in the region.

It is important for Washington to have Riyadh on board as President Obama considers them an important strategic ally and hopes to work closely with them on various regional policies, allowing US to continue its moderating influence in the oil markets.

Kerry met the Iranian Foreign Minister Mohammad Javed Zarif in Switzerland this Monday in hopes of finalising a frame work agreement by the end of March, as discussed in their meeting in Munich last month.

For more: US wants Iran to meet March N-deadline: Kerry

Kerry and Zarif have met many times over the past months, mostly in European capitals, as they have sought to hammer out a deal. Their political teams have also been negotiating behind the scenes.

The Saudi King has recently initiated dialogue between all major Sunni states in the Gulf region, meeting the King of Jordan and Presidents of Turkey and Egypt. It is widely believed that this is an attempt to bolster unity amongst the major Sunni states in face of a common threat; Iran.

Although Washington shares Arab concerns regarding Iran's alleged role in Syria and Yemen, and its ties to Lebanon's Hezbollah, the Arabs remain critical of US Iran nuclear talks. Any deal, they argue, would allow Iran to extend its influence in proxy states and escalate conflict.

“The Saudis fear Obama will give the Iranians a deal whatever the cost because it is important for his legacy, and that Iran will get a certain regional status in exchange for an agreement,” said a diplomat in the Gulf.

So far, Israel has been the main critic of a possible nuclear deal with prime minister Netanyahu launching a 3 day campaign in a bid to convince the Senate to block any such deal.

To read more: Netanyahu launches campaign to thwart Iran nuclear deal