Bloomberg | Golnar Motevalli: Iran�s top diplomats are touring neighboring countries, including three Arab Gulf monarchies, to try to shore up support after the U.S. announced plans to increase troop deployments in the region and sell weapons to some of the Islamic Republic�s top rivals.

Foreign Minister Mohammad Javad Zarif arrived in the Iraqi capital, Baghdad, late Saturday for meetings about the frictions, the semi-official Iranian Students� News Agency reported. On Sunday, his deputy, Abbas Araghchi, started a tour of Gulf Arab neighbors including Oman, Kuwait and Qatar, according to the state-run Islamic Republic News Agency.

In Baghdad, Zarif told reports Iran had proposed non-aggression pacts with all Gulf Arab neighbors, IRNA reported, in an apparent effort to limit any U.S.-led regional front against it.

Tehran�s regional diplomacy went into high gear as President Hassan Rouhani hinted that the Islamic Republic could hold a public referendum over the fate of the beleaguered 2015 nuclear deal that�s been crumbling since the U.S. quit it last year. Asked by a journalist whether he�d invoke a constitutional rule on a vote, Rouhani replied: �When this article should be used or whether it should�ve been used before is another matter.�

Tensions between the two countries, already high over President Donald Trump�s withdrawal from the nuclear accord that Iran had adhered to, deteriorated dramatically in recent weeks after the White House vowed to force Iran�s vital oil exports down to zero and revoked a series of key sanctions waivers. Frictions escalated even more this month after the U.S. claimed, without citing evidence, that Tehran was planning an escalated campaign against American interests in the region.

The U.S. has made a show of military force in the region, including the announcement Friday that it will send 1,500 additional troops and fighter jets to the region. That same day, the Trump administration also invoked emergency authority to advance the sale of billions of dollars of weapons to countries including Saudi Arabia and the U.A.E., citing the need to deter Iran�s �malign� activities in�the Middle East.

For the first time, U.S. officials also said publicly over the weekend that they think Iran is behind recent attacks on tankers in the Gulf and a pipeline in Saudi Arabia.

Iran has responded by announcing limited steps to resume nuclear activity restricted under the agreement. It also set a deadline to start its own gradual withdrawal from the deal unless Europe can guarantee the agreement can function.

Zarif left for Iraq immediately after returning from a visit with officials in Pakistan. Departing Islamabad last night, he called the planned U.S. troop buildup �extremely dangerous and a threat to international peace and security.�

In Baghdad, Zarif�s Iraqi counterpart, Mohamad Alhakim, said his country was ready to act as a mediator between Iran and the U.S. to help ease strains, Iraqi TV reported.