Secretary of State Rex Tillerson, left, speaks during a news conference with Lebanese Prime Minister Saad Harir in Beirut on Feb. 15. (Bilal Hussein/AP)

Secretary of State Rex Tillerson met with Turkish President Recep Tayyip Erdogan for more than three hours Thursday night, trying to mend a relationship rubbed raw over Syria and other hot-button issues.

Returning to his Ankara hotel after 11 p.m., Tillerson declined to discuss the meeting when reporters waiting in the lobby asked him to talk briefly about it.

“Not tonight — we’re still working,” he replied.

Relations between the two countries were already tense. Turkey has accused the United States of helping stage an attempted coup and detained Turks who work for the U.S. Embassy and consulates.

But the relationship has taken a nose-dive since Turkish forces went on an offensive against a U.S.-backed Kurdish militia in Syria that the Turks consider terrorists. Tillerson has made numerous conciliatory statements throughout his week-long trip to the Middle East, expressing understanding for their concerns.

Turkish officials responded with pugnacious retorts over what Foreign Minister Mevlut Cavusoglu warned is a make-or-break moment in the U.S.-Turkey relationship. Erdogan kept up the tough rhetoric, threatening an “Ottoman slap” if U.S. troops interfered in Turkey’s moves against the Syrian Kurdish fighters.

Tillerson has more meetings with Cavusoglu scheduled for Friday.

Earlier Thursday during a stop in Beirut, Tillerson urged Lebanon to distance itself from the Hezbollah militia as he met with political allies of the group.

“Hezbollah’s presence in Syria has only perpetuated the bloodshed, increased the displacement of innocent people and propped up the barbaric” regime of Bashar al-Assad, Tillerson said in a news conference with Lebanese Prime Minister Saad Hariri, whose coalition government includes the group.

“Their presence in Iraq and Yemen has also fueled violence,” Tillerson said. “And the consequences of Hezbollah’s involvement in these far-off conflicts — which have nothing to do with Lebanon — are felt here.”

Tillerson’s Middle East swing represents an effort to push back against Iran’s influence in the region, a major component of U.S. policy. It is one reason the United States will maintain a military presence in Syria long after Islamic State militants are routed. Hezbollah poses a threat to neighboring Israel, and the militia fought in Syria alongside the Lebanese army against Islamic State fighters.

This month, the Trump administration imposed sanctions on individuals associated with Hezbollah, which the United States designated as a terrorist group two decades ago. The move was described by officials as a first step in the administration’s efforts to battle Iran’s support for armed groups throughout the region.