US Secretary of State John Kerry is heading to Egypt and Qatar to meet the foreign ministers of both countries, with a nuclear deal with Iran topping the agenda of the talks.
Kerry, who arrives in Cairo on Saturday, will not be visiting Israel, Washington's main ally in the region and the primary foreign opponent of the Iran agreement.
US officials rejected suggestions that Kerry's omission of Israel from the itinerary signalled that the Obama administration had given up trying to convince Israeli leaders of the merits of the deal, the AP news agency reported.
The last time Kerry spoke with Israeli Prime Minister Benjamin Netanyahu was on July 16, two days after the Iran deal was concluded.
Officials reportedly said the trip was primarily designed to follow-up on a May meeting that US President Barack Obama hosted for Arab leaders at Camp David, at which the US tried to ease the worries of its Middle East allies over Iran.
The officials, who spoke on condition of anonymity because they were not authorised to discuss Kerry's trip publicly, said the talks in Qatar would take stock of progress made on those goals, particularly since the Iran deal was signed.
One US official said that Kerry would use the meeting with the foreign ministers of the Gulf Cooperation Council (GCC) to "try to respond to any remaining questions they might have, hopefully satisfy them and ensure that they are supporting our effort going forward".
Iranian Foreign Minister Mohammad Javad Zarif visited Kuwait, Qatar and Iraq in a similar tour earlier this week to talk to his counterparts about the nuclear deal.
New arms sale
Saudi Arabia is the largest and most influential member of the GCC and has been publicly supportive of the Iran deal, albeit with reservations.
Earlier in the week, the US State Department authorised the sale to Saudi Arabia of $5.4bn in Patriot missiles and related equipment, along with $500m in ammunition.
Kerry's first stop will be in Cairo where he will participate on Sunday in a strategic dialogue with Egyptian officials that has been on hiatus because of political unrest since 2009.
Despite continuing human rights concerns, the Obama administration is increasing military assistance to Egypt as Cairo confronts growing threats from armed groups, particularly on the Sinai peninsula.
Sinai-based fighters have launched increasingly sophisticated attacks in recent months that have killed dozens of Egyptian soldiers and police.
The latest wave of violence began after the military overthrew President Mohamed Morsi two years ago.
After leaving the Middle East, Kerry will travel to Southeast Asia, stopping in Singapore, Malaysia and Vietnam before returning to Washington.