A bipartisan group of US senators signed a letter on Thursday encouraging Canadian Prime Minister Justin Trudeau to increase and accelerate defense spending in accordance with the North Atlantic Treaty Organization (NATO).

The letter was written ahead of the NATO summit scheduled for July and was spearheaded by Democratic Senator Jeanne Shaheen and Republican Senator Thom Tillis, who serve as co-chairs of the US Senate NATO Observers Group.

The 23 senators who signed the letter called on the Canadian government to uphold the NATO parties’ commitment to “strengthen our collective security by increasing defense spending levels to two percent of each country’s gross domestic product (GDP).” The senators pointed out that Canada is a founding member of NATO and remains a “valued ally” that has “long contributed to essential NATO operations around the world.”

The letter also noted, however, that NATO is facing “one of the most severe threat landscapes in its history,” and therefore all NATO allies must uphold their commitments. The senators emphasized their unwavering commitment to the alliance, stating, “Canada will fail to meet its obligation to the alliance, to the detriment of all NATO Allies and the free world, without immediate and meaningful action to increase defense spending.”

When questioned about the letter, Canada’s Deference Minister Bill Blair referred to an April policy announcement by the Trudeau government, promising additional billions for the armed forces.

Canada announced in April that its military spending is expected to rise just 1.7 percent, and the senators emphasized that they were “concerned and profoundly disappointed” about the most recent projection.

NATO previously estimated in 2023 that only 11 members reached or exceeded the spending level. The organization also established guidance for members’ defense spending, with at least 66 percent of countries expected to meet the goal this year.