Turkey’s demand for the extradition of cleric Fethullah Gulen, whom it has denounced as the terrorist mastermind behind July’s thwarted coup attempt, is generating considerable tension with the U.S. government.

Even as Vice President Joe Biden arrived in Ankara to promise American cooperation, Turkish President Recep Tayyip Erdogan declared the U.S. has “no excuse” to refuse Fethullah Gulen’s extradition, and his Prime Minister, Binali Yildirim, was issuing veiled threats about anti-American sentiment growing in Turkey if Gulen is not handed over.

Biden declared that the Obama administration has “no interest whatsoever in protecting anyone who has done harm to an ally, none,” but added that U.S. legal proceedings must be followed — a process legal experts say could take several years, with input from both judges and the U.S. State Department, according to Reuters.

Biden declared that Turkey’s government has agreed to respect that complex legal process. “Let’s give them some time. I believe they mean what they say. And so let’s move on,” he said from Ankara.

Erdogan and Yildirim don’t sound like they’re interested in “moving on” at all.

Erdogan said the U.S. has “no excuse” for refusing Turkey’s request, adding that “our relations with the United States are on the level of strategic partnership and the refusal to extradite Gulen would not contribute to it.”

Yildirim suggested the U.S. ought to “accelerate” the “extradition process of this terrorist leader” because that would help the Turkish people “quickly recover from their sadness and disappointment.”

Interestingly, State Department spokesman Mark Toner said on Tuesday that the extradition request already filed for Gulen by Turkey is not directly related to the July 15 coup but was related to other charges from Turkish authorities, which Toner did not specify.

According to Reuters, Turkey’s Justice Minister said another extradition request, this time directly related to the coup, will be filed next week.

It won’t exactly help to smooth things over with the United States that Turkey has begun shelling U.S.-supported Kurdish forces in Syria. Rudaw reported on Tuesday that the Turkish military pounded Kurdish YPG positions north of Manbij with at least 20 artillery strikes. This was no accidental shelling of a melee between the Kurds and ISIS — Turkey deliberately targeted an ally of the United States.

As Rudaw explains, Turkey has drawn a proverbial line in the sand around the town of Jarabulus, currently held by the Islamic State, but soon to be attacked by Free Syrian Army forces supported by Ankara. The Turks have not been shy about linking the YPG militia in Syria to the Kurdish PKK separatists currently battling security forces inside Turkey.

Turkish Foreign Minister Mevlut Cavusoglu explicitly threatened heavier attacks against the YPG if they remain within striking range of Jarabulus, promising that if “YPG doesn’t retreat to the east of the Euphrates, Turkey will do what’s necessary.”

Turkey might have a lot more than artillery barrages in store for America’s allies in Syria. The Syrian government is complaining about the violation of its territorial integrity after twenty Turkish tanks rolled across the border on Wednesday, ostensibly to support the Free Syrian Army in its push to capture Jarabulus. By Wednesday afternoon, FSA forces claimed they had succeeded in driving ISIS out of the city, with help from Turkish tanks and warplanes.

The Syrian government regards the Free Syrian Army as no less a “terrorist organization” than ISIS.

Politico reports followers of Fethullah Gulen are complaining of death threats and intimidation all across Europe, mostly at the hand of other Turkish immigrants loyal to the Erdogan government. Politico writes: 

Cultural centers, schools, associations and shops linked to Gülen’s Hizmet movement have reported insults on social networks, death threats, arson attacks on their cars and stones thrown at their premises. There have also been calls to boycott shops owned by Gülenist Turks, and some parents have withdrawn their children from schools run by the Gülen network.

It would not be surprising to see Erdogan, Yildirim, or other Turkish ministers mention that unfortunate state of affairs, the next time they urge the United States to speed up the 75-year-old Gulen’s extradition.