ATHENS, Greece (AP) — Greek Prime Minister Kyriakos Mitsotakis on Monday pledged to keep up military support for Ukraine for as long as it takes and to help with post-war reconstruction. During his talks in Athens with President Volodymyr Zelenskyy, the Ukrainian leader suggested Greece could help train his country’s fighter pilots on new Western aircraft.

Zelenskyy flew to Athens for his fourth visit to a European Union capital in three days, where he later attended an informal meeting of Balkan leaders with top European Union officials.

In statements following talks with Zelenskyy, Mitsotakis voiced full support for Kyiv against Russia’s invasion and condemned Russian “war crimes.” He pledged to “stay on the side of the government and the heroic people” of Ukraine, “however much time may be required.”

Mitsotakis also said NATO-member Greece would participate in the “titanic” task of reconstruction in Ukraine when the fighting is over.

Zelenskyy thanked Mitsotakis for Greece’s support, and suggested that Athens has agreed to train Ukrainian pilots to fly the U.S.-made F-16 warplanes that Denmark and the Netherlands pledged to provide to Kyiv.

“Today we have an important result for the aviation coalition — Greece will take part in training our pilots on F-16s,” he said. “Thank you for this offer.”

Greek officials did not respond to requests for comment, and Mitsotakis made no reference to pilot training.

Zelenskyy and Mitsotakis also signed a joint declaration on Greece supporting Ukraine’s NATO accession, “when allies agree and conditions are met.”

In the evening, Zelenskyy joined an informal dinner organized by Mitsotakis for nine Balkan leaders, European Commission President Ursula von der Leyen and European Council head Charles Michel.

The dinner was to discuss the Western Balkans’ future in the EU, which many of the region’s countries have already joined and the rest are jockeying to enter.

Greece has joined its NATO and EU partners in strongly backing Ukraine against the Russian invasion and has provided military assistance in the form of armored personnel carriers and ammunition.

But Athens has resisted pressure to provide Kyiv with a Russian-made air defense missile system stationed on the southern island of Crete. Greece is engaged in a substantial weapons procurement program of its own amid testy relations with neighboring Turkey — its NATO ally and historic regional rival.

Earlier on Monday, Zelenskyy was in Denmark, where he thanked lawmakers for helping his country resist Russia’s invasion. On Sunday, Denmark and the Netherlands announced they would provide Kyiv with F-16 warplanes that could be delivered around the end of the year.

The presidents of Serbia, Montenegro and Moldova, the prime ministers of North Macedonia, Kosovo, Bulgaria, Croatia and Romania, and the head of the council of ministers of Bosnia and Herzegovina attended Monday’s dinner. Mitsotakis was also meeting several of them individually on Monday and Tuesday.

A notable absence was Albanian Prime Minister Edi Rama. Relations between Greece and its northwestern neighbor have soured over the jailing of ethnic Greek minority leader Fredi Beleri, who was arrested before local elections in May on vote-buying allegations.

Beleri was elected mayor of the southwestern Albanian town of Himara despite being in pre-trial detention. Athens insists his detention is politically motivated and has called for his release.

“I believe we all understand that it was not possible to invite Mr. Rama to such an important initiative,” Greek government spokesperson Pavlos Marinakis said.

“When we say that Albania’s European path passes through the basic respect of European rules and the rules of justice, we mean it,” he added, noting that Albania’s president had declined an invitation to attend.