Erdogan flew in from Kuwait and was expected to meet Qatar's Emir Sheikh Tamim bin Hamad Al Thani on Wednesday, according to the Turkish leader's office.

"Turkey has been trying to negotiate to acquire some of Qatar's used Eurofighters," the source told AFP, speaking on condition of anonymity because they were not authorised to talk to journalists.

"In exchange, Turkey has offered access to its new-generation fighter jet, the Kaan, as part of a potential technology transfer arrangement."

So far "no concrete progress" had been made with the negotiations still ongoing, the source said.

Turkey wants to modernise its air force and has in recent years sought to buy 40 new Eurofighter Typhoons built by a four-nation consortium of Germany, Britain, Spain and Italy.

The move came after Washington booted Ankara out of its F-35 fighter programme in 2019 over Turkey's purchase of an S-400 Russian surface-to-air missile defence system.

The purchase had raised fears it would give NATO's main adversary a window into Western jet operations.

-'Strategic bluff'-

Some defence observers see Turkey's push to acquire the Eurofighters as a strategic bluff aimed at putting pressure on Washington to readmit Ankara to its fighter jet programme.

"For Turkey, the main priority remains the F-16 and F-35 programmes," the Turkish source said.

In May, Erdogan expressed confidence that the sanctions would quickly be ended, and his meeting last month with US President Donald Trump further cemented those hopes.

Washington's Turkey Ambassador Tom Barrack said in June that US sanctions were likely to be over by the year's end.

But the Turkish source said it was likely to take a bit longer.

"Due to the current political gridlock in the US Congress, progress on these deals is unlikely before the new year."

In 2017, Qatar placed an order for 24 Eurofighter jets, and in December, Doha reportedly said it was looking to acquire another 12 more, according to several defence news outlets.

Ankara's request might receive a lukewarm reception, according to the Turkish source, in light of Qatar's own defence requirements following Israeli strikes on Hamas figures in the emirate last month.