It remains to be seen just how lasting and severe President Donald Trump’s turn against Vladimir Putin will be. Trump has criticized the Russian president in unprecedented terms in recent days and signaled he’ll send vital weapons to Ukraine.

President Trump reveals how Russian leader 'talks nice, then bombs everybody' as the U.S. prepares to send Ukraine Patriot missiles under a NATO agreement.

But his frustration with Putin has grown. Last week, the president said the United States was taking “a lot of bullshit” from Putin. Today, he authorized a significant shipment of U.S. defensive weapons to Ukraine via NATO and threatened Russia with new tariffs if the war does not end in 50 days.

“Putin will not negotiate as a loser,” one of his longtime associates tells TIME by phone from Moscow. “He knows that winners don’t get punished, and if he wins, all of this” — the sanctions, the tariffs — “will go away.”

President Trump discussed how he came to give up on negotiating with Vladimir Putin, during a meeting with NATO Secretary General Mark Rutte at the White House on Monday, as the U.S. agrees to sell new and more weapons to Europe and Ukraine.

Trump's threat against Russia runs parallel to a Senate-led effort to pass crippling sanctions on countries that buy Russian energy.

U.S. President Donald Trump repeatedly said during his campaign he would be able to end the war between Russia and Ukraine “in 24 hours” upon taking office.

President Trump is hosting NATO Secretary General Mark Rutte at the White House on Monday as the U.S. agrees to sell new and more weapons to Europe and Ukraine.