NATO will kick off an exercise on Monday to defend its newly expanded Nordic territory when more than 20,000 soldiers from 13 nations take part in drills lasting nearly two weeks in the northern regions of Finland, Norway and Sweden.

One of three Swedish Air Force JAS 39 Gripen fighter aircraft takes off from the Blekinge Wing F17, based in Kallinge southern Sweden for a base in Sardinia to join the Nato-led operation in Libya, 

With over 4,000 Finnish soldiers taking part, the Norway-led Nordic Response 2024 represents the NATO newcomer's largest ever participation in a foreign exercise, according to Finland's military.

“For the first time, Finland will participate as a NATO member nation in exercising collective defense of the alliance’s regions,” the Finnish Defense Forces said in a statement.

Finland, which shares a 1,340-kilometer (830-mile) border with Russia, joined NATO in April 2023 in a historic move following decades of military non-alignment. With its bid now ratified by all NATO members, neighboring Sweden is currently finalizing formalities to enter the military alliance as its 32nd member — most likely in March.

Both Sweden and Finland had developed strong ties with NATO after the end of the Cold War, but public opinion remained firmly against full membership until Russia's invasion of Ukraine.

Nonalignment was seen as the best way to avoid tensions with Russia, their powerful neighbor in the Baltic Sea region. But the Russian aggression caused a dramatic shift in public opinion in both countries, and they applied jointly for NATO membership in May 2022.

For years, the biannual NATO drill, which has been conducted in the Arctic extremes of northern Norway, was called “Cold Response.”

However, “thanks to the NATO expansion with Finland and eventually Sweden, we are now expanding the exercise to a Nordic Response,” the Norwegian Armed Forces said on its website. This year, the drill is hosted equally by Finland, Norway and Sweden.

Swedish Prime Minister Ulf Kristersson, left, speaks during a press conference with NATO Secretary General Jens Stoltenberg at the Swedish Government headquarters Rosenbad in Stockholm, Oct. 24, 2023. Hungary's parliament approved Sweden's application to join NATO on Monday, Feb. 26, 2024, paving the way for the Scandinavian country to become the alliance's 32nd member.

The participating nations in the exercise that runs through March 15 are Belgium, Britain, Canada, Denmark, Finland, France, Germany, Italy, the Netherlands, Norway, Spain, Sweden and the United States.

Roughly half of the participating troops will drill on land. The rest will train at sea, with over 50 participating submarines, frigates, corvettes, aircraft carriers, and various amphibious vessels, and in the air with more than 100 fighter jets, transport aircraft, maritime surveillance aircraft and helicopters, according to the Norwegian military.

The combined joint training will focus on the defense and protection of the Nordic region, Norwegian military officials said.

“We need to be able to fight back and stop anyone who tries to challenge our borders, values and democracy,” said Brigadier Tron Strand from the Royal Norwegian Air Force, Commander of the Norwegian Air Operations Center, in a statement. “With the current security situation in Europe, the exercise is extremely relevant and more important than ever before,” he added.

“The High North represents an important and strategically located area for NATO” and the Nordic Response 2024 exercise “increases Nordic preparedness and the capability to conduct large-scale joint operations in challenging weather and climate," NATO said on its website.

Finland’s new president, Alexander Stubb, will inspect the drill together with Norwegian Prime Minister Jonas Gahr Støre in northern Norway on March 7. It’s the first foreign trip for Stubb since he was sworn in as Finland’s new head of state and its supreme military commander on March 1.