Turkish President Recep Tayyip Erdogan said on Saturday if Ankara and Washington were to join forces they could turn the Syrian city of Raqqa into a "graveyard" for the Islamic State of Iraq and the Levant (ISIL).
Erdogan also suggested he could launch cross-border operations against Kurdish rebels at any time, just days after the Turkish military carried out air strikes in Syria and Iraq, drawing concern from the United States.
"America, the coalition, and Turkey can join hands and turn Raqqa into a graveyard for [ISIL]," Erdogan told a business summit in Istanbul.
"They [ISIL] will look for a place to hide."
Erdogan's comments come in advance of a meeting with US President Donald Trump on May 16 - their first face-to-face summit since the real estate mogul and reality TV star took office in January.
Ankara is hopeful about a relationship with Washington under Trump after ties frayed in the final years of Barack Obama's administration, which limited cooperation between the NATO allies.
The two countries have bitterly disagreed over the role of the Kurdish People's Protection Units (YPG) in Syria.
Turkey views the YPG as the Syrian extension of the Kurdish PKK group, which has waged a deadly rebellion against the Turkish state since 1984.
But the US is concerned that Turkey's military operations in Syria are more focused on preventing Syrian Kurds from forming an autonomous region in northern Syria, along Turkey's border, which could embolden Turkey's own Kurdish minority.
Erdogan said he would present Trump at their meeting next month with "documents" proving YPG's links to the PKK, which is designated a "terrorist" group by Ankara and Washington.
"We are telling American friends not to take a terror group along with them," the Turkish leader said.
On Wednesday, Turkey carried out several air strikes in Syria and Iraq against separatist Kurdish rebels and their allies, drawing the wrath of US officials who accused Ankara of lacklustre coordination.
The strikes in the Sinjar area of northern Iraq were against positions held by the Yazidi Protection Units, a militia supported by the PKK.
"We launched strikes against Sinjar and the other place [in Syria] and killed 210 to 220 terrorists there. Why? You cannot play with this nation," Erdogan said.
He hinted at future operations against YPG and PKK in Iraq and Syria.
"We know very well what to do when the right time comes. We can turn up abruptly one night," he said, quoting a line from a well-known Turkish song.
Northern Syria is one of the most complicated battlefields of the multi-sided Syrian war, with ISIL now being fought there by the Syrian army, Turkey and its rebel allies, and an alliance of US-backed Syrian militias.
Source: News agencies