Istanbul (CNN) US Secretary of State Mike Pompeo called his Turkish counterpart Saturday to discuss Syria, a conversation that comes at a time of increased tensions between the two NATO allies over the planned US withdrawal from that country.

"The Turkish Minister of Foreign Affairs Mevlut Cavusoglu spoke to Pompeo about the latest developments in Syria," said a brief statement from Turkey's foreign ministry.

Pompeo's call with Cavusoglu came as the top US diplomat continues a marathon Middle East tour, which has taken him to Cairo, Bahrain and the United Arab Emirates. He is also expected to travel to Saudi Arabia.

In a high-profile speech Thursday in Cairo, Pompeo insisted there had been no contradiction in the shifting US strategy in Syria or confusion about it despite the shocked response to the move from allies in the Middle East and beyond.

Iran and Syria

Addressing reporters Saturday in the UAE capital, Pompeo said the goal of expelling "every last Iranian boot" from Syria was an ambitious objective but insisted it was the US mission. He did not go into detail about how it would be achieved. He also repeated the argument that the withdrawal of US troops from Syria was just a "tactical change."

Pompeo pointed to a forum of nations set for February to address instability in the region. The United States and Poland will jointly host the Ministerial to Promote a Future of Peace and Security in the Middle East

"We're going to have an important ministerial in Warsaw on February 13 and 14 where there will be dozens of countries ... from nearly every continent," Pompeo told reporters Saturday in an off-camera briefing.

"There'll be countries from Asia and Western Hemisphere and certainly from the Middle East and from Africa and from Europe all attending. And we'll talk about lots of issues, including how it is we together can get Iran to behave like a normal nation."

He said the coalition "is big and growing and the tools that we get from having that coalition working together to complete that mission give us an opportunity to create that chance for the Iranian people."

Pompeo was asked if these efforts were more of a "holistic" way to expel the Iranians without the United States necessarily taking the lead.

"That's right. We're happy to be an important part of it. It's an important part of President Trump's agenda. The nuclear proliferation risks from Iran are incredibly real," he said.

Referring to the Iran nuclear deal from which the US has withdrawn, Pompeo said, "The previous arrangement that was struck was wholly inadequate to prevent those proliferation (risks). So our mission set (is) certainly to stop the terror regime, to stop the funding of Hezbollah, Shia militias and Houthis -- funding the Houthis in Yemen "

Strained relations

US demands that the Kurds be protected after US forces leave Syria have worsened already strained relations with Turkey.

Pompeo told Egyptian state television Friday he planned to speak to the Turkish foreign minister to come to a "common understanding" about the execution of Trump's decision to withdraw US troops from Syria in an "orderly and productive" way.

Turkish President Recep Tayyip Erdogan publicly blasted US national security adviser John Bolton on Tuesday for saying the US withdrawal was contingent upon Turkey's pledge not to attack US-backed Kurdish fighters in Syria once American troops go home.

Turkey considers several Kurdish groups -- including the People's Protection Units, also known as the YPG -- to be terrorist organizations.

The YPG is the backbone of the Syrian Democratic Forces, which is the main US partner on the ground in the battle against ISIS and has controlled a large swath of northern Syria for the past several years.

Pompeo confirmed Saturday that the US special envoy for Syria, James Jeffrey, was in the country, adding that the diplomat would travel back to Ankara before too long.

Bolton said earlier in the week that Jeffrey's trip to Syria would be to reassure the Kurds that the United States was not abandoning them.

Kurds' morale hit

Kurds on the front lines of the fight against ISIS in Syria have told CNN their morale has taken a hit as they seek protection by strengthening other alliances -- including with the regime of Syrian President Bashar al-Assad and the Russians.

Meanwhile, US Gulf allies, including the UAE, have been ramping up their engagement with the Assad regime since Trump announced the US drawdown on December 19, as US leverage on Syria is now seen as waning.