Norway is joining France’s plans to cooperate more closely with European countries on nuclear deterrence, the two countries’ leaders announced on Wednesday.

The addition of Norway, which is traditionally very close to the United States, to the initiative is yet another example of how European countries are rethinking their security strategies in light of Russia’s war on Ukraine and concerns about the Trump administration’s reliability.

“Along with nine other European countries, Norway will participate in your initiative on how French nuclear weapons can contribute to security and deterrence in Europe,” Norwegian Prime Minister Jonas Gahr Støre told reporters in Paris, standing next to French President Emmanuel Macron.

“Russia’s largest nuclear arsenal is located in the High North, just a few kilometers from Norway,” he said, adding that Norway would continue to primarily rely on NATO for its security.

On March 2, the French president announced that Germany, Poland, Greece, the Netherlands, Belgium, Denmark and Sweden had agreed to discuss nuclear cooperation with Paris. That could include joint nuclear drills, information sharing and, ultimately, the potential temporary deployment of French nuclear-capable Rafale fighter jets in allied countries — a concept the French called “forward nuclear deterrence.”

Since then, highly classified talks about exactly what the cooperation will entail have already begun with some nations, two officials told POLITICO.

On Wednesday, Paris and Oslo also signed a wide-ranging bilateral defense and security deal — dubbed the Narvik agreement — that includes a mutual assistance clause, more dialogue between their armed forces and cooperation on air defense, space and Arctic security, Macron said. In the past few years, the French president has sought to increase his country’s defense ties with Nordic countries, including Denmark, Finland and Sweden.

Støre told Norwegian news agency NTB earlier on Wednesday: “We are ​doing this in light of the security policy situation in Europe, including Russia’s massive rearmament, also in the nuclear domain, and that it is waging a ​full-scale war against another European country.”

He added that no nuclear weapons would be deployed on Norwegian soil during peacetime.

Milena Wälde contributed to this report.