Turkish President Recep Tayyip Erdogan Tuesday said a sanctions-busting court case in New York involving Turkish nationals is a “political coup attempt” against him and his government. With Erdogan also threatening military action against a key U.S. ally in Syria, relations between the NATO allies could deteriorate further.

Erdogan alleged the conviction of a Turkish state banker in the federal case is the latest attempt by the FBI and CIA to unseat him. He made the comment while addressing members of his AK Party in parliament.

“Those who could not succeed in the military coup attempt in Turkey on July 15 [2016], are now searching for a different attempt in our country, he said. He cited the case in the U.S. as “the address of this political coup attempt.”

Ankara also accuses Washington of collaborating with U.S.-based Turkish cleric Fethullah Gulen in the 2016 failed coup that left an estimated 150 people dead. The U.S. denies the accusation.Turkey has asked the U.S. to extradite Gulen, who lives in self-imposed exile in Pennsylvania and has denied all involvement in the coup attempt.

Bilateral relations between the NATO allies, already deeply strained since the coup attempt, have been further exacerbated by the conviction in New York of Mehmet Hakan Atilla, a senior executive of Halkbank, on charges of violating U.S. sanctions against Iran.

The repercussions of that conviction could lead to a further ratcheting up of tensions, warned analyst Atilla Yesilada of Global Source Partners.

“I see an escalation of the crisis,” he said. “The United States could threaten a wide range of sanctions; even the threat would cast a long shadow on the Turkish banking system. There would be immense difficulties for Turkish entities to borrow abroad.”

Turkey needs to borrow around $16 billion a month to cover its financial obligations.

Erdogan also threatened Tuesday to attack the Syrian Kurdish militia, the YPG, a key U.S. ally in the war against Islamic State. Ankara considers the militia a terrorist organization linked to an ongoing insurgency in Turkey.

Diplomatic columnist Semih Idiz of the al-Monitor website said the threat could be an effort to pressure Washington

“There is definite brinkmanship on the part of Turkey,” he said. “There is no doubt about that and there is no guarantee it will get what it wants. But Ankara is banking on the fact that Turkey is vitally strategic for Washington and somewhere it can’t be avoided, not that Turkey is courting Russia and all this. So I think Erdogan is trying to apply pressure to reduce whatever penalty is coming.”

To U.S. unease, Turkey is increasingly deepening relations with Russia. Erdogan is also looking to France after a visit last week to Paris, with pro-government media touting France as a more reliable ally than the United States.

But with both Paris and Moscow also supporting the Syrian Kurdish militia, analysts suggest Ankara is unlikely to carry out its threats against the group. They say if the current deterioration in relations with Washington continues, Ankara’s search for other allies is likely to intensify.