WASHINGTON >> The first time he spoke to Volodymyr Zelenskyy, President Donald Trump tried to pressure Ukraine’s new leader to dig up dirt on Joe Biden ahead of the 2020 election. It was a 2019 phone call that eventually sparked an impeachment.

On Monday, Trump ordered a “pause” to U.S. assistance to Ukraine as he seeks to pressure Zelenskyy to engage in negotiations to end the war with Russia — casting doubt on future support from Washington to Kyiv in fending off Russia’s invasion.

That followed Friday’s disastrous Oval Office meeting, in which Trump and Vice President JD Vance tore into Zelenskyy for what they perceived as insufficient gratitude for the more than $180 billion U.S. has appropriated for military aid and other assistance to Kyiv since the start of Russia’s war in Ukraine in 2022.

Trump, a Republican, has since slammed Zelenskyy for suggesting that the end of the war likely “is still very, very far away.” Ukraine’s leader says it would take time to come to an agreement to end the war as he tried to offer a positive take on its relationship with the U.S. after the White House blowup last week.

And Vance has increased the pressure, and sparked uproar in Europe, by suggested that a critical minerals agreement the Trump administration has pushed — but that Zelenskyy left Washington without signing on Friday — “is a way better security guarantee than 20,000 troops from some random country that hasn’t fought a war in 30 or 40 years.”

The vice president was referring to an international security force for post-war Ukraine proposed by key allies Britain and France.

A look at the evolution of Trump and Zelenskyy’s relationship over the years:

‘Perfect’ phone call

In July 2019, Zelenskyy was anxious for a meeting with Trump at the White House, one of the Ukrainian leader’s top foreign policy priorities at the time.

During a 30-minute call, Trump dangled the possibility of a face-to-face meeting. But he also suggested that future U.S. military support for Ukraine might be contingent on its leader helping investigate business dealings there by Hunter Biden, the former vice president’s son.

The elder Biden was competing for the Democratic presidential nomination, and Trump seemed to want to weaken him 15 months out from Election Day.

Trump denied wrongdoing and began referring to his exchange with Zelenskyy as a “perfect” phone call. Even Zelenskyy later insisted that he faced “no blackmail.”

But Trump was impeached by the Democratic-controlled House in December 2019 on abuse of power and obstruction of justice charges, only the third American commander in chief to be in that situation. He was acquitted by the Senate.

Russia’s war in Ukraine

Russia launched a full-scale invasion of Ukraine on Feb. 24, 2022, triggering the biggest conflict on the European continent since World War II.

Since then, the U.S. has provided tens of billions of dollars in military assistance to Ukraine. The Biden administration made steadfast military and political support for Zelenskyy’s country a centerpiece of his foreign policy.

As the war raged, the Biden White House staunchly defended continuing to provide support to Ukraine, even as some Republicans began grumbling about so much funding for a war that had no end in sight.

In a speech to Congress in December 2022, Zelenskyy thanked “every American” for supporting his country.

“Your money is not charity,” he said then. “It’s an investment in the global security and democracy that we handle in the most responsible way.”

Trump, then campaigning for his second term, said repeatedly that Russia would never have invaded Ukraine if he’d been president and that he’d have no trouble solving the conflict.

Upon taking office, he upended years of U.S. policy by dispatching negotiators to Saudi Arabia to meet with officials from Russian President Vladimir Putin’s government, and also began hammering out the minerals deal that he and Zelenskyy had planned to sign Friday.