Turkish President Recep Tayyib Erdogan indicated for the first time Monday that his country may have traded Islamic State group prisoners it held captive in exchange for 49 Turkish hostages held by the militants.

Asked about it in New York on Monday, Erdogan said “such things may be possible.” He said Israel released 1,500 Palestinian prisoners in exchange for one Israeli hostage. “So you see, it’s possible,” he added.

The hostages – 46 Turks and three Iraqis – were returned to Turkey on Saturday after more than three months in the hands of the Islamic State group, which captured them when it overran the Iraqi city of Mosul in June.

Turkish government officials have not revealed how they managed to secure the release of the captives. Erdogan denied paying a ransom but has been vague on whether there was a prisoner swap.

Speaking at the Council of Foreign Relations in New York, Erdogan tried to sidestep the question.

“This process that took 102 days involved an operation by the national intelligence agency … it was a historic, very important process,” he said.

Erdogan stressed that no payment was involved. “As to the rest, you probably cannot expect us to publicly divulge what the international agencies do in their business but the end result is that 49 diplomatic consular staff have been released.”

Pressed further, he acknowledge that there may have been a prisoners swap.

“Such things may be possible,” he said.

What Turkey may or may not have done to secure the release has been a subject of speculation. Many observers expressed disbelief that the ruthless militant group would have relinquished such a big bargaining chip without getting something in return.

Asked about joining the international coalition to fight the Islamic State group in Syria, Erdogan said Turkey has “no hesitation whatsoever when it comes to fighting terrorism.”

He said Turkey has been unjustly criticized for not being clearer on the subject “because we were mindful of the safety of our citizens.”

“This is a systematic attack on turkey’s international reputation,” he said.

U.S. Secretary of State John Kerry said Monday that he expects Turkey to step up in the fight against the Islamic State group now that Turkey has secured the hostages’ release.

Turkey, a U.S. ally and NATO member, has made commitments at various regional conferences to help in the effort against the Islamic State group but the help has been limited so far because “they first needed to deal with their hostage situation,” Kerry said in an appearance on MSNBC.

“Now the proof will be in the pudding,” Kerry said.

(AP)