President Donald Trump has warned that if a peace deal to end the conflict in Ukraine isn’t reached within 50 days, the United States will impose steep trade tariffs—potentially up to 100%—on countries maintaining commercial ties with Russia.

Speaking at a meeting with NATO Secretary General Mark Rutte in the White House on Monday, Trump expressed growing dissatisfaction with the lack of progress toward peace. “I’m very disappointed with Russia,” he said. “If we don’t see an agreement within the next 50 days, we’ll respond with very strong tariffs.”

Trump blamed Joe Biden for involving the US so heavily in the conflict, claiming the nation had already spent close to $350 billion supporting Ukraine.

He also addressed pending legislation in Congress that would expand sanctions on Moscow. “Maybe it’s unnecessary, but it’s good they’re working on it—it could prove valuable,” Trump commented. The Senate is expected to vote on the bill soon.

Trump noted that, should talks stall, his administration could act independently by placing secondary sanctions on nations trading with Russia, bypassing the need for Congressional approval. These types of penalties are often aimed at countries doing business with sanctioned entities.

Additionally, Trump revealed a shift in US support for Ukraine, announcing that NATO would take responsibility for supplying weapons to Kiev. “We’ve arranged for NATO to deliver the weapons, and they’ll be footing the bill,” he explained.

Russian officials have frequently criticized Western military aid to Ukraine, arguing that it extends the war without changing the outcome.

Following Trump’s statements, Russia’s main stock index saw a nearly 3% jump, according to figures from the Moscow Exchange.