Ukraine's President Volodymyr Zelenskiy appears on-screen as he speaks during the Warsaw Security Forum, in Warsaw, Poland September 29, 2025. Agencja Wyborcza.pl/Dawid Zuchowicz/via REUTERS

By Anna Koper and Barbara Erling

WARSAW (Reuters) -Ukraine has proposed building a joint air defence shield with allies to protect against threats from Russia, Ukrainian President Volodymyr Zelenskiy said on Monday, after a series of airspace incursions that caused alarm on NATO's eastern flank.

NATO leaders have said that Russia has been testing the alliance's readiness and resolve with airspace incursions in Poland and the Baltic states, and Kyiv says its experience in dealing with aerial threats would be valuable.

"Ukraine proposes to Poland and all our partners to build a joint, fully reliable shield against Russian aerial threats," he said in an address to the Warsaw Security Forum delivered via video link.

"This is possible. Ukraine can counter all kinds of Russian drones and missiles and if we act together in the region we will have enough weapons and production capacity."

Ukraine has already said that its troops and engineers will train Polish counterparts on countering drones.

Romania, meanwhile, aims to partner with Ukraine to build drones under a new European Union defence funding mechanism.

Romanian Defence Minister Ionut Mosteanu told the Warsaw Security Forum that new drone fragments were found in the eastern Romanian county of Tulcea, neighbouring Ukraine, on Monday.

The topic of defence cooperation with Kyiv was high on the agenda as leaders gathered in Warsaw for the annual security forum.

German Defence Minister Boris Pistorius told the conference that "Europe's and Ukraine's defence industry must work together more closely and effectively".

"The European Union must back this by providing a much more flexible regulatory framework for the defence industry in Europe."

Following the Russian incursions into NATO airspace, countries on the alliance's eastern flank have agreed on the need for a "drone wall" with advanced detection, tracking and interception capabilities.

Polish Defence Minister Wladyslaw Kosiniak-Kamysz said Ukrainian participation would be essential to the project.

"Polish-Ukrainian cooperation in this area already exists, but we expect... there to be cooperation between the European Union and Ukraine," he said.

"Otherwise, we will have dangerous spaces, we will have gaps in the air, missile and anti-drone defence systems."

However, Pistorius warned that establishing a drone wall would not be a quick process.

"We're not talking about a concept that will be realised within the next three or four years," he said. "We need to prioritise, and recognise that we require more capabilities and capacities than previously described."

(Reporting by Anna Koper and Barbara Erling in Warsaw, Olena Harmash in Kyiv, Kirsti Knolle in Berlin, Luiza Ilie in Bucharest, writing by Alan Charlish; Editing by Ros Russell, Aidan Lewis)