One of Europe’s largest aerospace and defense industry associations has welcomed its first Ukrainian firm as a member, at a time when allies are under pressure to reassure Kyiv of their long-term commitment to help fend off Russia’s invasion.

Antonov, Ukraine’s biggest aircraft manufacturer, joined the Aerospace, Security and Defence Industries Association of Europe this week, according to the lobby group, which counts companies including Airbus SE, BAE Systems Plc and Rheinmetall AG as members.

“I warmly welcome Antonov as a new ASD member, an important step towards the integration of the Ukrainian aerospace industry in the European industrial ecosystem,” ASD Secretary General Jan Pie said in a statement published Friday.

Ukrainian President Volodymyr Zelenskiy met with European leaders in Granada, Spain this week to press for continued military support, amid concerns about the continued flow of US aid. European backing for Ukraine also faces a new challenge after Robert Fico, a candidate sympathetic to Russia, won Slovakia’s general election.

Antonov’s membership of the ASD is the latest example of closer industrial cooperation between European and Ukrainian manufacturers.

The company constructed the world’s biggest aircraft, the Antonov-225 cargo plane, which Ukraine’s state-run defense group Ukroboronprom said was destroyed by Russian forces in the early stages of the war.

Read More: World’s Biggest Plane Destroyed in Russian Attack on Airfield

European defense contractors have recently signed agreements with Ukrainian companies to help with maintenance and manufacturing directly in Ukraine.

Dusseldorf-based Rheinmetall and Ukroboronprom are establishing a joint venture to maintain and repair vehicles that Germany supplies to Ukraine and also to eventually produce Rheinmetall armaments in Ukraine.