Turkey has rejected a key demand by several Arab states involved in a major dispute with Qatar, saying Ankara has no plans to shut down its military base in the small Gulf country.
The demand that Turkey pull out its forces was one of a steep list of ultimatums from Saudi Arabia and others who have cut ties with Doha that they say must be fulfilled within the next 10 days.
Qatar has confirmed receiving the 13-point list of demands on Thursday from Kuwait, which is mediating the dispute, but has not yet commented on them.
The list says Turkey's military base in Qatar must be closed immediately, and insists that Doha also shutter broadcaster Al-Jazeera, cut back diplomatic relations with Iran and sever all ties with the Muslim Brotherhood.
Turkish defence minister Fikri Isik said that the Turkish base aims to train Qatari soldiers and increase the tiny Persian Gulf nation's security.
According to the Milliyet newspaper's online edition, he also said that "no-one should be disturbed by" the Turkish presence in Qatar.
Turkey has sided with Qatar in the dispute and its parliament has ratified legislation allowing the deployment of Turkish troops to the base.
The military said a contingent of 23 soldiers reached Doha on Thursday.
Saudi Arabia, Egypt, the United Arab Emirates and Bahrain broke ties with Qatar and restricted access to land, sea and air routes earlier this month over allegations the Persian Gulf country funds terrorism - an accusation that US President Donald Trump has echoed.
The move has left Qatar, whose only land border is shared with Saudi Arabia, under a de facto blockade by its neighbours.
Qatar vehemently denies funding or supporting extremism.
But the country acknowledges that it allows members of some extremist groups such as Hamas to reside in Qatar, arguing that fostering dialogue with those groups is key to resolving global conflicts.
Those countries have now given Qatar 10 days to comply with all of the demands, which include paying an unspecified sum in compensation.
Underscoring the growing seriousness of the crisis, state-run Qatar Petroleum acknowledged early on Friday that some critically important employees "may have been asked to postpone" trips abroad "for operational reasons" as a result of the embargo against Qatar.
It described the move as "a very limited measure that could take place in any oil and gas operating company" to ensure uninterrupted energy supplies to customers.
Under Qatari law, foreigners working in the country must secure their employer's consent to receive an exit permit allowing them to leave.
The practice, which has been in place for years, has been assailed by rights groups who say it limits workers' freedom of movement and leaves them open to abuse.
The list included conditions that the gas-rich nation had already insisted would never be met, including shutting down Al-Jazeera.
Qatar's government has said it will not negotiate until Arab nations lift their blockade.
The demands were also likely to elicit Qatari objections that its neighbours are trying to dictate its sovereign affairs by imposing such far-reaching requirements.
"At the moment, there is no likelihood of bringing the matter back to the table," said Mr Isik.
Earlier this week, US secretary of state Rex Tillerson had warned the demands must be "reasonable and actionable", underscoring the American administration's frustration at how long it was taking Saudi Arabia and others to formalise a list of demands, complicating US efforts to bring about a resolution to the worst Gulf diplomatic crisis in years.
According to the list, Qatar must refuse to naturalise citizens from the four countries - Saudi Arabia, the United Arab Emirates, Bahrain and Egypt - and expel those currently in Qatar, in what the countries describe as an effort to keep Qatar from meddling in their internal affairs.
They are also demanding that Qatar hand over all individuals who are wanted by those four countries for terrorism; stop funding any extremist entities that are designated as terrorist groups by the US; and provide detailed information about opposition figures that Qatar has funded, ostensibly in Saudi Arabia and the other nations.
Qatar's neighbours have also accused it of backing al Qaida and Islamic State's ideology throughout the Middle East.
Those umbrella groups also appear on the list of entities whose ties with Qatar must be extinguished, along with Lebanon's Hezbollah and the al Qaida branch in Syria, once known as the Nusra Front.
More broadly, the list demands that Qatar align itself politically, economically and otherwise with the Gulf Co-operation Council, a regional club that has focused on countering the influence of Iran.
Saudi Arabia and other Sunni-led nations have accused Qatar of inappropriately close ties to Iran, a Shiite-led country and Saudi Arabia's regional foe.
The Iran provisions in the document say Qatar must shut down diplomatic posts in Iran, kick out from Qatar any members of Iran's elite Revolutionary Guard, and only conduct trade and commerce with Iran that complies with US sanctions.
Under the 2015 nuclear deal, nuclear-related sanctions on Iran were eased but other sanctions remain in place.
The Revolutionary Guard has deployed its forces to conflict zones such as Syria and Iraq. It is not known to have a presence in Qatar.
Cutting ties to Iran would prove incredibly difficult.
Qatar shares a massive offshore natural gas field with Iran, which supplies the small nation that will host the 2022 Fifa World Cup its wealth.
Also, not only must Qatar shut down the Doha-based satellite broadcaster, the list says, but also all of its affiliates.
That presumably would mean Qatar would have to close down Al-Jazeera's English-language sister network.
Supported by Qatar's government, Al-Jazeera is one of the most widely watched Arabic channels, but it has long drawn the ire of Middle East governments for airing alternative viewpoints.
The network's critics say it advances Qatar's goals by promoting Islamist movements such as the Muslim Brotherhood that pose a populist threat to rulers in other Arab countries.
The list also demands that Qatar stop funding a host of other news outlets including Arabi21 and Middle East Eye.
Beirut-based political analyst George Alam said Qatar is unlikely to agree to the demands.
"They are impossible to be met because they interfere in Qatar's foreign policy and Qatar considers its foreign policy a sovereign matter that is nonnegotiable, he said.
If Qatar agrees to comply, the list asserts that it will be audited once a month for the first year, and then once per quarter in the second year after it takes effect.
For the following 10 years, Qatar would be monitored annually for compliance.