Boeing is reluctant to share the technology used in the warheads it manufactures for the Patriot PAC-3 interceptor missiles which Ukraine and its Western supporters want to manufacture in Europe, German media outlet Die Welt has reported, citing sources.

US President Donald Trump announced earlier this month that Ukraine would receive a license to produce the coveted Patriot systems. Manufacturing is expected to be based in a European NATO country, potentially Germany, where the facilities would be considered safe from potential Russian attacks.

In a report on Wednesday, Die Welt correspondent Christoph Wanner outlined several obstacles facing the initiative, including what he described as Boeing Defense’s unwillingness to transfer sensitive technology to foreign partners.

Boeing manufactures the seeker warheads used in PAC-3 interceptors, while Lockheed Martin produces the missile bodies. Boeing Defense CEO Steve Parker recently said that the company intends to manufacture 850 of the warheads this year, compared with 650 in 2025.

Ukrainian leader Vladimir Zelensky has said Kiev needs an additional 300 interceptor missiles to sustain its air defenses through the coming winter.

Media reports have pointed to a worldwide shortage of Patriot interceptors and other costly US-made munitions. The supply crunch has reportedly intensified as a result of Washington’s ongoing conflict with Iran.

Germany remains one of the Ukrainian government’s main military donors as it is also seeking to expand its own armed forces, citing what officials describe as a growing threat from Russia. Berlin’s rearmament plans have faced financial pressures and a widespread public reluctance to volunteer for military service.

Moscow maintains that the Ukraine conflict was engineered by NATO as a proxy war against Russia. Russian officials have accused the bloc of using Ukrainians as “cannon fodder” while supplying Kiev with weapons, funding and intelligence.