NEW YORK

The U.S. and Turkey stressed cooperation between the two allies during a meeting Thursday of American and Turkish defense ministers.

Defense Secretary James Mattis welcomed his Turkish counterpart Fikri Isik at the Pentagon where they held a joint press conference that covered a broad range of security issues.

“This relationship continues today, with United States and Turkish military forces working together to counter a wide range of threats to our common security,” Mattis said.

“I also recognize and salute the humanity of the Turkish government and the Turkish people in managing the Syrian refugee flow and the associated humanitarian challenges,” the secretary said.

Turkey hosts nearly 3 million Syrian refugees, shouldering the largest load of the UN-backed global refugee response to the Syrian crisis.

Mattis called Turkey an essential NATO ally and a vital member of the anti-Daesh coalition. He praised U.S.-Turkey cooperation on the use of the Incirlik Air Base, as well as Turkish military contributions to Operation Euphrates Shield that Ankara launched last August to clear terrorists from its border with Syria.

“And I commend Turkey for its fast response to ensure the victims of the Assad regime's hateful chloric gas attack received treatment in Turkish hospitals,” Mattis added.

Turkey swiftly condemned the chemical weapons attack that killed scores last week in Khan Sheikhun.

Turkish authorities corroborated the use of a nerve agent in the affected region after the treatment of victims at the border in the presence of World Health Organization experts.

Isik expressed appreciation for the U.S. retaliatory response to the Syrian regime, which he said he hopes will “deter the regime from its barbaric attacks with or without chemical weapons”.

The U.S. last Thursday fired 59 Tomahawk missiles at a Syrian air base that American officials believe was used to carry out the chemical weapons attack.

During a speech at Turkish think tank SETA’s D.C. offices after the meeting with Mattis, Isik praised the U.S. strike, saying, “Donald Trump’s encouraging response has created a great deal of sympathy in the region.

“The U.S. response is extremely significant and it must be followed up,” Isik said.

The minister added that Turkey was nearing a decision whether to purchase air defense systems from Russia.

“Turkey urgently needs an air defense system,” Isik said. “We are at the final stages of deciding on this. Ultimately the decision will be made by the president and the prime minister,” he said regarding the purchase of the Russian S-400 system.

Isik noted he and Mattis “discussed as a priority” the issue of U.S. support for the PYD/YPG terror group as part of the Syrian Democratic Forces (SDF) in the fight against Daesh.

U.S. support for the YPG-backed SDF has long vexed Turkey that views the YPG -- the armed wing of the PYD -- as the Syrian offshoot of the PKK terrorist organization.

Turkey, the U.S. and the EU have designated the PKK a terror group, but neither the U.S. nor EU have followed Turkey's lead on the PYD/YPG.