Timing of Qatar F-15 deal more procedural than political

It added that US Defence Secretary Jim Mattis and Qatar's Defence Minister Khalid al-Attiyah had also discussed the current state of operations against the Islamic State of Iraq and the Levant (ISIL, also known as ISIS) and the importance of de-escalating tensions in the Gulf.

US President Donald Trump has signalled his support for the Saudi-led move but other US officials have been more cautious and called for dialogue to end the crisis. "Our expectation from King Salman is that he be the leader in solving this problem", Cavusoglu said at a joint news conference with his Tunisian counterpart.

The State Department previous year said it had authorized the sale of 72 F-15 Strike Eagle jets to Qatar.

"This is of course proof that U.S. institutions are with us but we have never doubted that", Reuters news agency quoted a Qatari official in Doha as saying.

"America's relationship with Qatar is built on the foundation of bilateral security agreements and Qatar's strong role in facilitating U.S. military forward deployment in the Middle East".

Last week, five Arab countries - Saudi Arabia, Egypt, the United Arab Emirates, Bahrain and Yemen - cut off ties with Qatar, accusing Doha of supporting terrorism. "America's support for Qatar is deep-rooted and not easily influenced by political changes".

In another development, Turkish Foreign Minister Mevlut Cavusoglu held talks in Doha with with Qatari Emir Sheikh Tamim bin Hamad al-Thani, Qatari Foreign Minister Sheikh Mohammed bin Abdulrahman Al-Thani and Economy and Trade Minister Sheikh Ahmed bin Jassim al-Thani.

Turkey is friendly to Qatar and has sent food supplies since the sanctions were imposed.

British foreign secretary Boris Johnson urged Gulf states including Saudi Arabia to ease their blockade of Qatar on Monday.

A statement to CNN from the Pentagon says the agreement will "increase security cooperation and interoperability between the United States and Qatar".