WASHINGTON (Reuters) - NATO Secretary General Jens Stoltenberg agreed with U.S. Secretary of State Rex Tillerson on Wednesday to look for a date that would allow all NATO allies to attend a meeting of foreign ministers.

NATO Secretary General Jens Stoltenberg listens to remarks at the morning ministerial plenary for the Global Coalition working to Defeat ISIS at the State Department in Washington, U.S., March 22, 2017. REUTERS/Joshua Roberts

Tillerson had initially decided to skip talks set for April 5-6 in Brussels, unsettling European allies who have questioned President Donald Trump’s commitment to the alliance. But the State Department said on Tuesday that Tillerson had proposed new dates for the talks, his first such NATO meeting.

“We have agreed to look into how we can solve this scheduling issue,” Stoltenberg told Reuters at a meeting to discuss the fight against Islamic State. “But I’m absolutely certain that we will find a date which works for all of the allies,” he said.

Stoltenberg sought to put to rest any ambiguity about the Trump administration’s commitment to NATO.

“There’s been a very clear and strong message from President Trump ... that the United States is ... strongly committed to NATO and to the Trans-Atlantic bond. This is not only in words, but also in deeds,” Stoltenberg said.

During his election campaign and on the eve of taking office in January, Trump called NATO “obsolete,” although he has since said he strongly supports the alliance. Trump has also pressed NATO members to meet spending targets.

At Wednesday’s meeting, Tillerson said the United States would set up “interim zones of stability” to help refugees return home in the next phase of the fight against Islamic State and al Qaeda in Syria and Iraq but he did not make clear where these zones were to be set up.

Stoltenberg also said the head of NATO’s military committee, Petr Pavel, recently held a telephone call with the chief of the Russian General Staff Valery Gerasimov .

Pavel said last month he hoped to hold the first telephone call in more than two years with Russia’s military chiefs in which he would outline why NATO believes its biggest military build-up since the end of the Cold War is not a threat to the Kremlin.

When asked when the phone call took place, Stoltenberg only said it was recent.

Worried since Russia’s 2014 seizure of Ukraine’s Crimea that Moscow could invade Poland or the Baltic states, NATO is bolstering its eastern flank with troops and war games and warehoused U.S. equipment ready for a rapid response force of up to 40,000 personnel.

A U.S.-led battalion of more than 1,100 soldiers will be deployed in Poland from the start of April, as the alliance sets up a new force in response to Moscow’s 2014 annexation of Crimea.

“And when tensions are high it’s even more important that we talk together and that we have open lines of military and political communications,” Stoltenberg said.

Russia says the alliance build-up threatens the stability of central Europe. It has some 330,000 troops amassed in its Western military district around Moscow, NATO believes.

Stoltenberg said it was too early to tell when the next meeting of the NATO-Russia Council, where the Russian ambassador to the North Atlantic alliance sits with member states’ envoys, would be.