HELSINKI (AP) — Sweden and Finland have joined a British-led military rapid reaction force that can either operate alone or jointly with the United Nations, NATO or the European Union.

The two non-NATO members joined the Joint Expeditionary Force on Friday when Sweden's Defense Minister Peter Hultqvist and his Finnish counterpart Jussi Niinisto signed a deal in Stockholm in the presence of British Defense Secretary Michael Fallon, who called it "a force of friends."

The unit can consist of up to 10,000 troops from Sweden, Finland, the Netherlands, Denmark, Norway, Estonia, Latvia and Lithuania. It can be used in combat, deterrence or humanitarian support.

In recent years, Finns and Swedes have strengthened their military cooperation with NATO and bilaterally with London and Washington, mainly due to neighboring Russia's behavior in the Baltic region.