Tensions between Ankara and Washington over the Turkish army's operation in Syria escalated further on Thursday as Turkey accused the White House of misrepresenting a phone call between Recep Tayyip Erdogan and Donald Trump.
The assault by Turkish troops against a Kurdish militia in northern Syria has seen Washington's fellow Nato member Ankara attacking a US-allied force, even raising fears of military confrontation between the two Alliance powers.
Turkey says it has made gradual progress in the offensive against Syrian Kurdish People's Protection Units (YPG) militia but has refused to give any time limit for the campaign.
After the Turkish and US presidents spoke late on Wednesday, the White House said Trump had urged Turkey to "to de-escalate, limit its military actions", expressing concern that the assault could harm the fight against jihadists.
But a Turkish official said the US statement did "not accurately reflect the content" of the call, adding that Trump did not share any concerns regarding "escalating violence".
Turkey launched an offensive against the YPG militia on Saturday in their enclave of Afrin, supporting Syrian rebels with air strikes and ground troops.
Ankara views the YPG as a terror group linked to the outlawed Kurdistan Workers' Party (PKK) inside Turkey. The PKK is blacklisted by Ankara and its Western allies.
But the YPG is still working closely with Washington against the Islamic State (IS) extremist group in Syria, in defiance of Turkey's warnings.
In a move that could further raise the stakes, Erdogan on Wednesday raised the prospect of an operation on Manbij, a YPG-held town to the east, where there is a US military presence.
'Risks giving life to IS'
On Thursday, Turkish Prime Minister Binali Yildirim hit out at the US "support for terror organisations", which "could not be accepted".
"The country we call an 'ally' in Nato is in cahoots with terror organisations," he said in a speech in Ankara.
"This is a grave and very painful situation. For a country like America to work with terror organisations is really very humiliating," Yildirim said.
Following the Erdogan-Trump telephone talks, the US envoy to the coalition against IS, Brett McGurk, said on Twitter the "prolonged operation risks giving life to ISIS (IS) as it's on verge of defeat".
"The US (is) now engaged intensively to urge restraint and de-escalation. We are prepared to work with Turkey on legitimate security concerns," he added.
Washington has more than 2,000 special forces and support troops inside Syria, mainly east of the Euphrates in an area also controlled by the YPG but separate from Afrin, which is west of the river.
In response to Erdogan's call on the US to stop supplying weapons to the YPG, Trump told the Turkish leader that "his country no longer supplied the group... and pledged not to resume" weapons delivery, the official said.
Trump also expressed concern about "the destructive and false" anti-American rhetoric emanating from Turkey, the White House said.
But the Turkish official said Trump "did not use the phrase 'destructive and false rhetoric coming from Turkey'", adding Trump said "open criticism" of the US "raised concerns".
As the operation entered its sixth day, an AFP correspondent saw tanks on the Turkish side of the border and soldiers ready to go into Syria amid tight security.
Turkish artillery fire pounded the Afrin region, state-run news agency Anadolu said.
Two people, a Turk and a Syrian, were killed on Wednesday after two rockets fired from Syria by the YPG landed in the border town of Kilis, province governor Mehmet Tekinarslan said.
Three Turkish soldiers have been killed since the start of the offensive while the Syrian Observatory for Human Rights has said 48 Ankara-backed Syrian rebels and 42 US-backed Syrian Democratic Forces (SDF) and YPG fighters had been killed.
The SDF is an umbrella grouping composed mainly of YPG.
Yildirim said over "300 terror organisation members were neutralised". He vowed Turkey would not allow a "terror structure on its southern border... whether it is east or west of the Euphrates".
The Observatory has said at least 30 civilians have been killed but Ankara strongly rejects such claims, saying that it is doing everything to avoid civilian casualties.