ISTANBUL: America's highest-ranking military officer sought on Monday to soothe strained ties with NATO ally Turkey, which was angered by the West's response to a failed military coup and an apparent US reluctance to hand over the cleric it says was responsible.

The fallout from the abortive coup on July 15, in which more than 230 people died as mutinous soldiers commandeered fighter jets, helicopters and tanks, has deepened a rift between Ankara and its Western allies.

President Tayyip Erdogan and many Turks have been frustrated by US and European criticism of a government crackdown in the aftermath of the attempted putsch in a country vital to the US-led fight against Islamic State and to stopping illegal migration to Europe.

They have accused Western leaders of being more concerned about the rights of the plotters than the gravity of the threat to a NATO member.

More than 60,000 people in the military, judiciary, civil service and education have been detained, suspended or placed under investigation since the coup, prompting fears that Erdogan is cracking down on all dissent.

"It is important that the United States, our friend and ally, display a clear and decisive stance against this terrorist coup attempt against our nation and democracy," Prime Minister Binali Yildirim told chairman of the US Joint Chiefs of Staff General Joseph Dunford during their meeting in Ankara.

Condemning the failed coup in Turkey, Dunford, the principal military adviser to the American president, said his visit was to show solidarity and added that the United States supports Turkish democracy, a statement from Yildirim's office said.

Earlier on Monday, about 150 protesters marched to the US Embassy in Ankara to protest Dunford's visit. "Coup plotter Dunford get out of Turkey," the crowd chanted.

"Dunford go home. Send us Fethullah," said one banner, in reference to U.S.-based Turkish cleric Fethullah Gulen, whose network of followers in the military and state institutions are blamed by Erdogan for orchestrating the coup plot.

The 75-year-old cleric, who has lived in self-imposed exile in Pennsylvania since 1999, denies involvement in the failed coup. President Barack Obama has said Washington will extradite him only if Turkey provides evidence of wrongdoing.

Dunford also met his Turkish counterpart and US personnel stationed at the Incirlik air base in southern Turkey, used by the U.S.-led coalition in the fight against Islamic State.

The scale of the purges, which have seen around 40 percent of generals and admirals dismissed, along with suggestions from officials that the death penalty may be reintroduced, have alarmed Western states nervous about Erdogan's tightening grip.

In Washington, Turkish lawmakers from the ruling party and the two largest opposition parties visited the US Justice Department on Monday, the first stop on a weeklong trip in which they will try to persuade US officials to support Gulen's extradition.

Turkey will send the United States new evidence within weeks, "if not days," proving that Gulen ordered the coup, said Taha Ozhan, the head of the delegation.

The evidence will be more recent than the documents Turkey has sent the US Justice Department so far, which all date from before July 15 and will include testimony and intercepted messages from alleged plotters who have been detained in Turkey, according to Ozhan.

"Through their messages, through their hidden communications, Turkish intelligence actually captured many (pieces of) evidence" that directly implicate Gulen, he said.

Senior Turkish officials rounded on Germany for preventing Erdogan from addressing a rally on Sunday of his supporters in Cologne via video link. Berlin's foreign ministry spokesman acknowledged relations were going through a "bumpy patch".

"'KILL US', THEY WILL BEG"

Turkish special forces overnight captured a group of 11 rebel commandos who had tried to seize or kill Erdogan during the coup. Drones and helicopters pinpointed them in forested hills around the Mediterranean resort of Marmaris after a two-week manhunt, an official said.

They were part of a group that attacked a hotel where Erdogan was holidaying on the night of the July 15 coup.

Video footage showed a dozen or so anti-coup demonstrators jeering the 11 detained soldiers, some of whom had swollen faces and bruises. The demonstrators waved Turkish flags and chanted "Traitors! We want the death penalty!"

Erdogan's crackdown after the failed coup has made European leaders even more uneasy about their dependence on the country to help stem illegal migration, in return for which Turks have been promised visa-free travel to the European Union.

CIVILIAN CONTROL OVER MILITARY

The coup attempt shocked Turkey, which last saw a violent military power grab in 1980, and shook international confidence in the stability of the country.

Nearly 1,400 more members of the armed forces were dismissed, and the top military council was stacked with government ministers on Sunday, moves designed by Erdogan to tighten civilian control over the military.

Turkey's defence ministry has changed the postings of 167 generals within the army on Monday, reshuffling senior ranking officers in key positions. Defence Minister Fikri Isik said expulsions from the army were not over.

"There will be more if necessary," he said in an interview with CNN Turk television. He added that a total of 311 soldiers were still at large following the coup attempt.

More than 1,700 military personnel were dishonourably discharged last week for their role in the putsch.

Erdogan has said Gulen harnessed his network of schools, charities and businesses, built up in Turkey and abroad over decades, to create a "parallel state" that aimed to take over the country.

However, the cleric has condemned the coup, and in an interview with CNN broadcast on Sunday repeated his denial that he had been involved in it.