Republican chairman of Senate Foreign Relations Committee says ‘recent disputes’ undermine US policy in the Middle East.

An influential Republican senator has announced he will withhold approval of US weapons sales to members of the Gulf Cooperation Council (GCC), until there is a clear path for settling the major diplomatic crisis with Qatar.

Tennessee Senator Bob Corker, chairman of the Senate Foreign Relations Committee, on Monday said in a letter to Secretary of State Rex Tillerson that “recent disputes” among GCC countries undermine efforts “to fight” the Islamic State of Iraq and the Levant (ISIL, also known as ISIS) armed group and “counter Iran”.

Corker said GCC member states devolved into conflict instead of seeking to ease regional tensions and expand their security cooperation.

READ MORE on the Qatar-Gulf crisis – All the latest updates

The GCC is an alliance of six Middle Eastern countries: Qatar, Saudi Arabia, the United Arab Emirates (UAE), Bahrain, Kuwait and Oman.

On June 5, three GCC members – Saudi Arabia, the UAE and Bahrain – along with Egypt, cut ties with Qatar over allegations that it funds “terrorism” – an accusation Doha strongly rejects but that President Donald Trump has echoed.

The move has left Qatar under a de facto blockade by its neighbours.

As chairman of the Foreign Relations Committee, Corker plays a central role in allowing or blocking US weapons sales.

“Congress has a particular power here, which is very important,” Al Jazeera’s James Bays, reporting from Washington, DC, said, adding that in his letter Corker was “careful” not to single out a specific country.

Nevertheless, he did write that the GCC had failed to “take advantage” of an Arab-Islamic-American summit last month in Saudi Arabia’s capital, Riyadh, where Trump and dozens of Arab and Muslim leaders discussed ways of rooting out “terrorism”, and “instead chose to devolve into conflict”.

“That seems to be an implicit criticism of those GCC members that decided to take action – Saudi Arabia, the UAE and Bahrain – and launched the attempt to blockade Qatar,” Bays said.

Corker and Tillerson have a close relationship, and they speak frequently on foreign policy issues [Reuters]

The country that could be “hurt the most” by Corker’s statement would be Saudi Arabia, which recently committed to buy $110bn worth of weapons from the US, our correspondent added. Saudi Arabia relies on US arms in its war in Yemen.

Qatar’s recent purchase of $15bn worth of F-15 fighter jets could also be affected, Bays said.

All Gulf states have acquired military equipment from the US, according to the US Congressional Research Service. Between 2012 to 2015, the US sold $300m worth of arms to Bahrain, $900m to Oman, $4.2bn to UAE, $4.4bn to Kuwait, $9.9bn to Qatar and $17bn to Saudi Arabia.

Senate endorsement

Once Congress is formally notified by the State Department of the sale of weapons to an ally, politicians typically have 30 days to review the transaction.

During that period they could pass a joint resolution or take other steps to stop the sale. If they take no action, the sale moves forward.

Corker told Tillerson that “before we provide any further clearances during the informal review period on sales of lethal military equipment to the GCC states, we need a better understanding of the path to resolve the current dispute and reunify” the alliance.

Rising tensions

The Saudi-Emirati-led bloc of countries has reportedly given Qatar 10 days to comply with 13 demands to end the crisis, insisting, among others, that Qatar shut down Al Jazeera, close a Turkish military base and scale down ties with Iran.

Qatari officials immediately dismissed the demands as neither reasonable nor actionable.

Tillerson said in a statement on Sunday that several of the demands Saudi Arabia and the other countries have placed on Qatar “will be very difficult to meet”.

Earlier this month, the Senate narrowly rejected a bipartisan attempt to rebuke Saudi Arabia, and scrap Trump’s plan to sell the kingdom more than $500m in precision-guided munitions.

The weapons are part of Trump’s proposed $110bn arms package to Riyadh, which the administration said would create US jobs while also improving a key ally’s military capability.