KYIV, Aug 17 - UN Secretary-General Antonio Guterres has arrived in Lviv in western Ukraine, where he will meet with President Volodymyr Zelenskiy and Turkish President Recep Tayyip Erdogan.

Guterres on Thursday will discuss the security situation at a Russian-occupied nuclear power plant in Zaporizhya and possible paths to end the Kremlin's nearly six-month invasion of Ukraine, RFE-RL reported.

The UN chief will visit a Ukrainian Black Sea port on August 19 that has recently resumed exports of grain following a halt caused by Russia's invasion.

Guterres and the international community have expressed deep concern over the risk of disaster at the Zaporizhya nuclear power plant, Europe's largest, amid reports of shelling and other dangers in the past week.

The United Nations has offered to help facilitate a visit by its International Atomic Energy Agency (IAEA) inspectors to Zaporizhya, but Moscow has dismissed a mission traveling through Kyiv despite vowing it would do all it could to help ensure IAEA access to the plant.

Zelenskiy earlier on August 16 accused Russia of "nuclear terrorism" in its actions, while Moscow says Ukrainian troops are responsible for artillery fire near the facility.

Exhausted Ukrainian workers at the Zaporizhya nuclear power plant have complained of being held at gunpoint.

Erdogan has repeatedly sought a role for his NATO-member state to mediate in the conflict, and Ankara was crucial to a recent deal that allowed for the restart of grain and fertilizer exports from three of Ukraine's Black Sea ports.

UN spokesman Stephane Dujarric said Guterres on August 20 will visit the joint coordination center in Istanbul that oversees the seaborne shipments.

The center is staffed by Russian, Ukrainian, Turkish, and UN officials.

The first ship to have left Ukraine under the multilateral deal two weeks ago was said by a shipping source and satellite data to have docked early on August 16 in the Syrian port of Tartus.

The ship, the Sierra Leone-flagged Razoni, departed Ukraine on August 1 and didn't unload in Lebanon as scheduled, but went dark before appearing in Tartus.

Russia is a key ally who has helped Syrian President Bashar al-Assad weather a brutal civil war and has a small naval facility at Tartus.

A UN-chartered ship loaded with 23,000 tons of Ukrainian grain, meanwhile, set sail on August 16 from a Black Sea port for Ethiopia, the first shipment of its kind in a program to assist countries facing famine, according to Ukraine's Infrastructure Ministry. (rfe-rl)