Switzerland wants to participate in the European Sky Shield air defense umbrella, the government said on Tuesday.
That move critics say runs counter to the country's long tradition of neutrality.
European Sky Shield is a joint air defense scheme created by Germany in 2022 to bolster European air defence, an issue that has come into sharper focus since Russia's invasion of Ukraine.
Swiss Defense Minister Viola Amherd is due to sign a declaration of intent to join the program during a meeting with her counterparts from Austria and Germany on Friday.
"Switzerland wishes to participate in the European Sky Shield Initiative and a declaration of intent is due to be signed in Bern," the Defence Ministry told Reuters, confirming an earlier report by broadcaster SRF.
Some 17 European countries have so far signed up to the Sky Shield project, including Germany, Britain, Finland, and Sweden.
It aims to cut costs for countries by coordinating their purchases of air and missile defense systems such as the Patriot missile system. It also aims to enable cooperation in training, maintenance, and logistics.
Neutral Switzerland has come under increasing pressure from its European neighbors since the Russian invasion in February 2022 to support Ukraine militarily by allowing re-exports of Swiss-made weapons.