The chairman of the US Senate Foreign Relations Committee said on Monday he would block arms sales to Saudi Arabia, the United Arab Emirates and other members of the Gulf Cooperation Council (GCC) pending progress in resolving a simmering dispute with Qatar.
"All countries in the region need to do more to combat terrorism, but recent disputes among the GCC countries only serve to hurt efforts to fight Daesh and counter Iran," Republican Senator Bob Corker wrote in a letter to Secretary of State Rex Tillerson.
His action could increase pressure on members of the Gulf Cooperation Council to settle the crisis. The GCC comprises Saudi Arabia, Kuwait, United Arab Emirates, Qatar, Bahrain and Oman.
Under US law, major foreign US arms sales are submitted for review to a small group of lawmakers, including the chairman of the Foreign Relations Committee, before they can go ahead.
Trump considered Corker as a potential vice president and secretary of state, and he works closely with the White House. The administration would be unlikely to ignore his resistance to the arms sales, and US officials said they considered his statement part of a broader effort to solve the Qatar crisis.
It was not immediately clear what sales would be affected. Trump has announced billions of dollars in arms sales since taking office in January. He sees weapons sales as a way to create jobs in the United States.
During Trump's recent visit to Saudi Arabia, Washington inked a massive, $110-billion arms deal with the kingdom.
Also earlier this month in a bid to reassure Qatar, the United States agreed to a $12-billion sale of F-15 jets to the emirate.
A Corker aide said his action would not affect sales that had already been reviewed by Congress or non-lethal assistance, including training. One sale already cleared by Congress was for up to $350 billion in precision-guided munitions and other offensive weapons to Saudi Arabia.
In his letter, Corker said he was pleased with Trump's recent trip to Saudi Arabia, which included a GCC summit.
"Unfortunately, the GCC did not take advantage of the summit and instead chose to devolve into conflict," Corker wrote.
Germany says Saudi demands "very provocative"
A list of 13 demands submitted by four Arab states to Qatar as a condition to lift their boycott on the Gulf country is "very provocative" because some items challenge Doha's sovereignty, German Foreign Minister Sigmar Gabriel said on Monday.
Saudi Arabia, the United Arab Emirates, Bahrain and Egypt imposed a boycott on Qatar three weeks ago, accusing it of backing militants – then issued an ultimatum, including demands that it shut down a Turkish military base in Doha.
Qatar denies the allegations and says the demands are aimed at curbing its sovereignty. A government spokesman last week said Doha was reviewing the list of demands but did not view them as reasonable or actionable.
The Arab states are demanding, among other things, that Doha close Al Jazeera television, curb ties with Iran, shut a Turkish base and also pay reparations.
Gabriel said it would be tough for Qatar to accept all 13 items on what he described as "a very provocative list."
He said efforts were under way to define which conditions Qatar could accept, and which it viewed as problematic.
Gabriel is due to meet Iranian Foreign Minister Mohammad Javad Zarif in Berlin on Tuesday.
Zarif earlier on Monday said that Europe should use its influence to defuse tensions in the Gulf, arguing that those countries that blamed Iran or Qatar for terrorism were trying to avoid taking responsibility for their own failures.
Iran's President Hassan Rouhani has also voiced support for Qatar in its confrontation with the four states. Qatar says it is being punished for straying from its neighbours' backing for authoritarian, hereditary and military rules.