European leaders are racing to figure out how to keep Ukraine supplied with weapons as U.S. President Donald Trump appears to be walking away from the war. One option: buy American.

Europe has neither the stocks of arms nor the capacity to make them in large enough volume as it becomes clear that the U.S. won’t be delivering any more. The White House has also refused Europe’s appeals to keep up the push to get Russian President Vladimir Putin to agree to an immediate ceasefire by stepping up sanctions.

Instead, the Kremlin seems to be stalling on peace talks promised to Trump as it prepares for a summer offensive, according to people familiar with the matter. A proposal that’s gaining more credence is to purchase more American systems — and then send those weapons on to Ukraine, said people familiar with the matter, who asked not to be identified discussing private deliberations.

The idea is that if Trump refuses to send U.S. weapons to Ukraine, Europe will.

That would help Ukraine deter Russia’s advance and might put fresh pressure on Putin to get serious about a ceasefire. And if the Europeans can persuade Trump to keep up supplying intelligence to Ukraine, President Volodymyr Zelenskyy may be able to hang on.

At the same time, the European Union is considering cutting more than 20 banks from SWIFT, the international payments system, as well as lowering a price cap on Russian oil and banning the Nord Stream gas pipelines as part of a new sanctions package to pressure Russia.

“It’s not entirely clear to me how bad it would be if the United States walks away while keeping open the possibility of allowing Europe or Ukraine to buy U.S. weapons and allows U.S. intelligence sharing with Ukraine to continue,” said Andrew Weiss, vice president for studies at the Carnegie Endowment for International Peace. “It’s not an ideal outcome. It’s certainly suboptimal, but it’s not the total worst case that a lot of us have been worried about.”

The pivot would essentially force Trump to pick between two competing desires: his desire to avoid antagonizing Putin against his wish to bring in more cash for the U.S. via the sale of big-ticket defense items.

Trump spoke separately earlier this week with Putin and European leaders, saying later that he would “back away” if sufficient progress was not made in negotiations between Russia and Ukraine. “This is a European situation,” the president said at the White House. “It should have remained a European situation.”