The Turkish Presidency said Zelenskiy will hold talks with President Tayyip Erdogan on the course of the Ukraine-Russia war, the Black Sea grain deal and bilateral relations, with the meeting scheduled for 1600 GMT.
Zelenskiy's office said the agenda included a peace formula aimed at ending the war with Russia, bilateral defence industry cooperation, and the release of Ukrainian prisoners of war held by Moscow.
Kyiv's Ukrinform state news agency said Zelenskiy had arrived in Istanbul and would visit a shipyard to see a corvette being built for Ukraine before meeting Erdogan.
"It is planned to convey that Turkey is continuing its efforts to end the war as soon as possible on the basis of negotiations," the source said.
Last week, Turkish Foreign Minister Hakan Fidan said after meeting Russian counterpart Sergei Lavrov that it was time for Ukraine and Russia to start ceasefire talks, but added that this must not mean the recognition of Russia's occupation.
The Turkish source said that among other items on the agenda for Zelenskiy and Erdogan are developments concerning a new regulation on the navigational safety of commercial ships between Russia and Ukraine, after the termination of the Black Sea Initiative.
Last July, Russia withdrew from that arrangement, which had allowed Ukraine to safely export grain from its Black Sea ports, saying its demands for better terms for its own food and fertiliser exports were being ignored.
Ankara has sought to persuade Russia to return to the arrangement, which was brokered by Turkey and the United Nations. Russia has said it was not interested in reviving it.
NATO member Turkey shares a maritime border with Ukraine and Russia in the Black Sea and has focused on maintaining good ties with both amid the war. It has provided military support for Kyiv while opposing the sanctions imposed on Russia.
As part of its balancing act Ankara has offered to host peace talks while keeping up its defence industry ties with Ukraine and deepening its energy cooperation with Russia, and it has inked an accord to take part in the post-war reconstruction of Ukraine.
"When peace returns to Ukraine, we aim to continue to be a strong supporter of the country's reconstruction efforts, based on our strategic partnership," the Turkish source said.
Zelenskiy's visit to Istanbul also comes before an expected visit by Russian President Vladimir Putin, which the Kremlin has said would be after Russian elections on March 15-17.
(Reporting by Tuvan Gumrukcu and Yuliia Dysa; Writing by Daren Butler; Editing by Ece Toksabay and Hugh Lawson)
