Russian President Vladimir Putin chairs a meeting of military officials at the Bocharov Ruchei presidential residence in Sochi, Russia, May 13, 2016. Mikhail Klimentyev/Sputnik/Kremlin via Reuters

Sweden and the U.S. signed a statement of intent Wednesday agreeing to closer defense collaboration with an eye toward Russian aggression and airspace violations across the European continent.

“This is a very important statement for Sweden, and it’s also something to show that the trans-Atlantic link is very important for Sweden and our part of Europe,” Defense News quoted Swedish Defense Minister Peter Hultqvist as saying. “We haven’t had this sort of umbrella before with the United States. We have had a lot of specific agreements, but not an overall umbrella.”

While the statement is nonbinding, it points to regional powers “testing their strength against their neighbors,” without specifically naming Russia. The agreement aims to boost the defense dialogue between the two countries, focus on airpower and cyberspace, and increase cooperation through military exercises and training.

“Swedish-U.S. combined efforts, including joint air, land and maritime exercises as well as operations and capability building missions, contribute to efforts to meet challenges to international peace and security,” the two nations said in the statement.

The agreement came as Sweden and neighboring states continue to warily eye Russian actions. Estonia said Wednesday that a Russian military aircraft had violated its airspace near the Gulf of Finland. Estonian officials said the Russian crew did not maintain radio contact with Estonian air traffic navigation officials. Russia denied any airspace violation while Estonia said the incident marked the third Russian airspace violation this year.

Sweden is not a member of the NATO military and political alliance, which launched its largest war games since the end of the Cold War in Poland this week. The exercises are scheduled to last 10 days and involve 31,000 troops. The U.S.-Swedish agreement called for developing multinational operations with partners including NATO.

Russia has continued to criticize NATO, viewing the alliance as encroaching on its sphere of influence. In response to NATO’s greater presence in Eastern Europe in recent months, Russia has begun construction of another military base, Reuters reported Wednesday.