Vice President Joe Biden called on Turkish authorities to be patient with the U.S. legal system as Turkey seeks the return of a cleric accused of masterminding last month's failed military coup.
Biden, who met with Turkish officials in Ankara on Wednesday, said the U.S. extradition process would take time as he reaffirmed Washington's cooperation in the case of U.S.-based Muslim cleric Fethullah Gulen. Gulen has denied any involvement in the July 15 coup attempt that killed more than 270 people.
"I understand the intense feeling your government and the people of Turkey have about him," Biden said at news conference after meeting with Turkish Prime Minister Binali Yildirim. "We are cooperating with Turkish authorities.
"Our legal experts are working right now with their Turkish counterparts on the production of and the evaluation of material and evidence that needs to be supplied to an American court to meet the requirements under our law in the extradition treaty to extradite Gulen."
Biden sought to assuage concerns that the U.S. was shielding Gulen.
"We have no, no, no, no interest whatsoever in protecting anyone who has done harm to an ally. None," he said. "But we need to meet the legal standard requirement under our law."
He also warned that President Barack Obama wouldn't intervene in the extradition process.
"We should make clear under American law that no president of the United States has authority to extradite anyone under his own power, that only an American court can do that.
"Were a president to attempt to do that, it would be an impeachable offense," he said.
Turkish officials, including President Recep Tayyip Erdogan, have repeatedly called on the U.S. to swiftly extradite Gulen, who lives in Pennsylvania in self-imposed exile.
In a joint news conference with Biden after their meeting, Erdogan said Turkey had already sent case files covering Gulen's alleged criminal activities prior to the July 15 coup.
"As per the extradition agreement between the U.S. and Turkey, these types of people should at least be detained, arrested and kept under surveillance," Erdogan said. "Yet that individual is still directing his terrorist organization from his whereabouts."
"He has schools, businesses and associations in 170 countries. He continues managing them. Many members of the media are interviewing them," Erdogan said.
The formal extradition request for his alleged involvement in the coup will be submitted next week, Turkish Justice Minister Bekir Bozdag said Wednesday.
"It's never understood that the wheels of justice move deliberately and slowly," Biden said. "It's totally understandable why the people of Turkey are angry. But there should be no doubt that we will continue to work closely with the Turkish government as this process unfolds."
Biden also rejected suggestions that the U.S. government knew about plans for a coup in advance.
"The United States of America did not have any fore-knowledge of what befell you on the 15th of July," he said.
Turkey's prime minister again called on the U.S. to speed up the process in the Gulen case.
"If the process can be sped up for (Gulen) to be returned to our country in order to be punished, if our cooperation in this regard continues to grow, then the Turkish people's sorrow, its disappointment in this regard will quickly give way to positive sentiments," Yildirim said.
During the visit, Biden addressed Turkish complaints that allies had not displayed strong solidarity with Turkey's elected leadership against the coup and apologized for not having arrived earlier.
"The United States stands with its ally Turkey," Biden said. "Our support is absolute and it is unwavering."
Earlier, Biden toured the sections of parliament damaged during the coup attempt.
A small group of young demonstrators protested Biden's motorcade as he headed to Yildirim's residence, the state-run Anadolu Agency reported. Anti-American sentiment has been on the rise in Turkey since the coup.
Biden hopes to smooth relations, but has limited leverage.
Cinar Kiper and Frank Griffiths contributed to this report.