A $12bn deal to buy US F-15 fighter jets shows Qatar has deep-rooted support from Washington, a Qatari official said on Thursday, Reuters news agency reported.

Qatar is facing an economic and diplomatic boycott by Saudi Arabia and its regional allies who cut ties last week, in the worst rift among Gulf Arab states in years.

Qatar hires law firm to counter terrorism accusations

They accuse Qatar of “funding terrorism”, fomenting regional unrest and cosying up to their enemy Iran, all of which Qatar denies.

Trump has echoed the accusations against Qatar, even as his defence and state departments have tried to remain neutral in the dispute among key allies.

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

“America’s support for Qatar is deep-rooted and not easily influenced by political changes.”

The Pentagon said the jets sale would increase security cooperation between the US and Qatar and help them operate together.

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.