'Stronger together': Polish leader Duda visits Ukraine ahead of NATO summit

Poland's president emphasised the need for unity with Ukraine on Sunday as he visited the country ahead of a NATO summit where Kyiv is hoping to get a clear signal that it could one day join the alliance.

"We are stronger together," President Andrzej Duda said on social media, as he visited the western city of Lutsk with Ukrainian counterpart Volodymyr Zelensky.

Poland is one of Ukraine's biggest supporters within NATO and has said it wants "security guarantees" for the country from other NATO members.

Zelensky returned from Turkey on Saturday after a regional tour to drum up support ahead of the summit with Western allies, who have pledged billions in military aid.

Zelensky was accompanied by five top commanders from the Azov regiment who were supposed to have remained in Turkey until the end of the conflict under a prisoner exchange deal with Moscow.

Their return to Ukraine angered the Kremlin, with spokesman Dmitry Peskov quoted by Russian news agencies on Saturday as saying that it was "a direct violation" of the agreement with Turkey.

One of the men, Denys Prokopenko, was quoted by Interfax Ukraine news agency as saying that he would return to the front.

"That is why we have come back to Ukraine. It is our main aim," said Prokopenko, who along with the others had been living in Turkey since September.

Peskov said the return was linked to the "failure" of Ukraine's counteroffensive, and Ankara's desire to show "solidarity" ahead of the NATO summit in Lithuania.

"Preparations for the NATO summit are underway and of course there has been a lot of pressure on Turkey," he said.

Biden headed to NATO summit 

US President Joe Biden is expected in Vilnius on Monday along with other NATO leaders for talks Tuesday and Wednesday.

Zelensky has said he does not expect Ukraine to actually join NATO until after the war but he hopes the summit will give a "clear signal" on the intention to bring Ukraine into the alliance.

The Ukrainian leader hailed Ukraine as "the country of the brave" in a video clip released on social media on Saturday, the 500th day of the war.

The video showed him visiting Snake Island in the Black Sea - a symbol of Ukraine's defiance against Russia.

The island was captured by Russian forces shortly after the start of the invasion.

A radio exchange went viral in which Ukrainian soldiers told the crew of Russia's attacking warship demanding their surrender to go away, using a swearword.

The Ukrainian soldiers were taken prisoner but later exchanged for Russian captives and the island was recaptured by Ukrainian forces in June last year.

Danger 'for many years' 

Zelensky on Friday secured Turkey's backing for Ukraine's NATO aspirations after winning a US pledge for cluster munitions that could inflict significant damage to Russian forces.

Washington's decision to supply Ukraine with cluster bombs - banned across a large part of the world - dramatically ups the stakes in the war.

Biden admitted that it had been "a difficult decision", while humanitarian groups strongly condemned it.

Cambodian Prime Minister Hun Sen, whose country still grapples with deadly war remnants, on Sunday urged Ukraine not to use cluster bombs.

"It would be the greatest danger for Ukrainians for many years or up to a hundred years if cluster bombs are used in Russian-occupied areas in the territory of Ukraine," Hun Sen tweeted.

He cited Cambodia's "painful experience" of US cluster munitions dropped in the early 1970s, a foreign legacy that has left tens of thousands maimed or killed.

Russia, which itself uses cluster munitions in Ukraine, said the decision was an "act of desperation" that would have "no effect" on the conflict.

Russian foreign ministry spokeswoman Maria Zakharova on Sunday urged NATO leaders instead to discuss the situation at the Zaporizhzhia nuclear power station in southern Ukraine.

Kyiv and Moscow have accused each other of planning a provocation at the site, raising alarm over the risk of a disaster at Europe's largest nuclear plant.

"The NATO summit should have focused on this topic. After all, the vast majority of Alliance members would be in the direct contamination zone," Zakharova said on social media.

The plant is held by Russian forces, who accuse Ukraine of regularly shelling the site. Kyiv has accused Moscow of rigging up the site with explosives.