MOSCOW, March 19 (AFP) - Russian President Vladimir Putin made a surprise visit to Mariupol, state media reported Sunday, his first to the city since it was captured after a lengthy siege at the start of Moscow's offensive in Ukraine.

The trip comes after an arrest warrant was issued for Putin by the International Criminal Court, over Russia's alleged deportation of thousands of Ukrainian children during the conflict.

Russia besieged Mariupol at the start of its offensive last year, destroying the Azovstal steel works, the last holdout of Ukrainian forces in the city.

According to state news agency TASS on Sunday, Putin flew to Mariupol by helicopter on Saturday and took a tour of the city, at times driving a car.

He visited several sites and spoke with residents, and was presented with a report on the reconstruction work of the city.

Putin's stop in Mariupol comes after his surprise visit to Crimea on Saturday to mark the ninth anniversary of the peninsula's annexation.

Russian state TV showed him visiting the Black Sea port city of Sevastopol, accompanied by the local Moscow-appointed governor Mikhail Razvozhayev.

Razvozhayev said on the messaging app Telegram that Putin had been expected to take part in the opening of a children's art school by video link.

"But Vladimir Vladimirovich came in person. Himself. Behind the wheel. Because on such a historic day, the president is always with Sevastopol and the people of Sevastopol," he said.

Russia annexed Crimea in 2014 following a referendum that was not recognised by Kyiv and the international community.

Addressing the World Economic Forum in Switzerland in January, Ukraine's President Volodymyr Zelensky said he aimed to take back Crimea, though Moscow has refused to include it in possible peace talks.

- 'Void' ICC warrant -

Putin's visit came after the International Criminal Court issued an arrest warrant for him on Friday over the "deportation" of Ukrainian children.

Kyiv says more than 16,000 Ukrainian children have been deported to Russia since the start of the conflict in February 2022, many of them placed in institutions and foster homes.

ICC prosecutor Karim Khan told AFP that Putin was now liable for arrest if he set foot in any of the court's more than 120 member states.

The 70-year-old Russian leader has not commented publicly on the warrant, but the Kremlin dismissed its validity as "void" since Russia did not recognise the ICC's jurisdiction.

The Hague-based court's decision came ahead of Chinese leader Xi Jinping's visit to Moscow on Monday to sign accords touted as ushering in a new era of ties.

China, a major Russian ally, has sought to position itself as a neutral party in the Ukraine conflict, urging Moscow and Kyiv to open negotiations.

But Western leaders have repeatedly criticised Beijing for failing to condemn Russia's offensive, accusing it of providing Moscow with diplomatic cover for its campaign.

- Grain deal extended -

In Ankara, Turkish President Recep Tayyip Erdogan said the two sides had agreed to extend a deal that has allowed Ukraine, a major grain exporter, to resume exports after its Black Sea ports were blocked by Russian warships.

But there was disagreement over the terms.

Ukraine's infrastructure minister said the deal had been extended for 120 days, but a spokeswoman for Russia's foreign ministry said Moscow had agreed to a 60-day extension.

The deal brokered by Turkey and the United Nations in July 2022 had allowed for the safe passage of exports, and had already been extended for 120 days in November.

The fighting is now concentrated in the eastern Donetsk region of Ukraine, particularly the city of Bakhmut.

Russian strikes hit the nearby city of Kramatorsk on Saturday, killing two people and wounding 10, said regional governor Pavlo Kyrylenko, who accused Moscow of using cluster bombs in the attack.

AFP journalists in Kramatorsk heard around 10 explosions go off nearly simultaneously just before 4:00 pm local time (1400 GMT) and saw smoke rise above a park in the southern part of the city.

A woman died at the scene from her wounds, they saw.