ANKARA (Reuters) — Turkish President Tayyip Erdogan urged his Russian counterpart Vladimir Putin on Sunday to declare a cease-fire in Ukraine, open humanitarian corridors and sign a peace agreement, his office said.

NATO member Turkey shares a maritime border with Russia and Ukraine in the Black Sea and has good ties with both. Ankara has called Russia’s invasion unacceptable and offered to host talks, but has opposed sanctions on Moscow.

In a statement after a one-hour phone call, the Turkish presidency said Erdogan told Putin that Turkey was ready to contribute to a peaceful resolution of the conflict.

“President Erdogan, who said an immediate cease-fire 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 cease-fire, 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 cease-fire 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 defence, 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.