US Secretary of State John Kerry is set begin a tour of the Middle East in an attempt to remove misgivings over the Iran nuclear deal reached in Vienna.
Kerry will talk to the foreign ministers of Arab nations which are sceptical of the deal, but he has skipped visiting Israel, the country primarily wary of the nuclear agreement.
The Obama administration has tried to play down the fact that Israel does not figure in Kerry's travel plan.
"This is an opportunity, really, for the secretary to do a deep dive with the GCC foreign ministers to try to respond to any remaining questions that they might have and hopefully to satisfy them and ensure that they're supporting our effort going forward," a US State Department official said, according to AFP.
Kerry will start his five-nation tour in Egypt, where he will hold talks with his counterpart Sameh Shoukry on a range of issues including the security situation and military aid.
He will meet other Arab leaders on Monday, 3 August, to allay fears over the Iran nuclear deal.
Earlier, Kerry said in his testimony to the House Foreign Affairs Committee: "I understand the fear. But we believe what we have laid out here is a way of making Israel and the region, in fact, safer."
The security situation in Iraq and Syria will also be discussed during the talks in Doha, Qatar. Kerry will meet Russian Foreign Minister Sergei Lavrov on the sidelines of the meeting to discuss various issues.
The final leg of Kerry's trip will take him to Southeast Asian nations Singapore, Malaysia and Vietnam.