According to his office, Turkish President Tayyip Erdogan encouraged his Russian counterpart Vladimir Putin on Sunday to proclaim a truce in Ukraine, create humanitarian corridors, and sign a peace accord.

Turkey, a NATO member, has a maritime border with Russia and Ukraine in the Black Sea and maintains friendly relations with both. Ankara has condemned Russia’s incursion and offered to host discussions, but it opposes sanctions against Moscow.

The Turkish president stated in a statement following a one-hour phone discussion that Erdogan informed Putin that Turkey was ready to help to a peaceful resolution of the situation.

“President Erdogan, who said an immediate ceasefire will not only ease humanitarian concerns in the region but also give the search for a political solution an opportunity, renewed his call of ‘let’s pave the way for peace together’,” his office said.

“Erdogan emphasized the importance of taking urgent steps to achieve a ceasefire, open humanitarian corridors and sign a peace agreement,” it said.

The Kremlin said Putin told Erdogan that Russia would only halt its military operation if Ukraine stopped fighting and if Moscow’s demand were met, adding the operation was going to plan.

Russia calls its assault a “special military operation”. It has uprooted more than 1.5 million people, in what the United Nations says is the fastest growing refugee crisis in Europe since World War Two.

Turkey has said it would be “naive” to expect results from the Ukraine-Russia negotiations while the fighting continues. Turkey’s defense minister on Sunday said an urgent ceasefire was needed so Ankara could evacuate its citizens from Ukraine.

Erdogan, who has called Putin a “friend”, had last spoken to the Russian leader on Feb. 23, a day before Russia launched its invasion. The call makes Erdogan the third NATO leader to speak to Putin since his offensive, following the leaders of Germany and France.

While forging close ties with Russia on defense, trade and energy, and hosting millions of Russian tourists every year, Turkey has also sold drones to Ukraine, angering Moscow, and opposes Russian policies in Syria and Libya, as well as its 2014 annexation of Crimea.

Turkey has said it wants to bring together foreign ministers from Ukraine and Russia for talks at a diplomacy forum next week in southern Turkey. Both countries have welcomed the offer, but Ankara says it is unclear whether they will be able to attend.