Former Ukrainian Prime Minister Yulia Tymoshenko | Sean Gallup/Getty Images Trump tells Ukrainian politician he won’t lift Russia sanctions The president appears to take a harsher stance on Russia in an unusual private meeting.

During an unusual private meeting on the sidelines of Thursday’s National Prayer Breakfast, President Donald Trump promised a Ukrainian opposition leader that the United States won’t lift sanctions on Russia until it pulls out of Ukraine, according to three people briefed on the meeting.

Within hours of meeting with both Trump and Vice President Mike Pence at the prayer breakfast, former Ukrainian Prime Minister Yulia Tymoshenko relayed the contents of the meeting to separate audiences at the Heritage Foundation and the Hudson Institute, according to people who attended the off-the-record events at the conservative think tanks.

The sources said that Tymoshenko, a member of parliament who is positioning herself for a presidential campaign against the beleaguered incumbent president Petro Poroshenko, told the think tanks that Trump assured her he would “not abandon” Ukraine, which claims that Russian troops are responsible for increased fighting in the region near the countries’ shared border. The international community largely supports this view, but Moscow denies it and blames the fighting on Russian separatists.

While Trump had suggested during his campaign that he might be willing to ease sanctions against Russia related to its aggression against Ukraine, Tymoshenko said Trump assured her he would do no such thing — unless Russia withdrew from Ukraine, according to the people who attended the briefings.

They said Tymoshenko, who is generally regarded as pro-Western, did not discuss specifics at the think tank events, which were by invitation only and were closed to the press. Notably, it was unclear whether the conditions indicated by Trump to Tymoshenko for lifting sanctions included Russian withdrawal from Crimea, a Ukrainian territory to the country’s south, which was annexed by Russia in 2014.

Still, one person who heard from Tymoshenko after the prayer breakfast, said “she definitely came away from her little tete-a-tete with Trump feeling somewhat calmer about the situation.”

And Tymoshenko’s characterization of her meetings with Trump and Pence would seem to mark a harsher tone towards Russia than the new president previously has struck publicly.

A Trump White House official would not discuss the specifics of the meeting, instead explaining “the President and the former Prime Minister had a brief, informal photo-op meeting in the reception before the National Prayer Breakfast. While no formal assurances were given, the United States remains concerned about violence in Eastern Ukraine.”

While Trump’s ambassador to the United Nations Nikki Haley this week rebuked Russia and declared the U.S. would leave in place its sanctions related to the annexation of Crimea, Trump himself has been much less confrontational.

Trump has expressed admiration for Russian president Vladimir Putin, indicated a willingness to consider easing the sanctions and at times disputed U.S. intelligence findings that Russian intelligence facilitated cyberattacks on Democratic officials and groups in an effort to boost Trump’s campaign against Democrat Hillary Clinton. And Trump’s Treasury Department this week tweaked sanctions levied by the Obama administration on a Russian spy agency in retaliation for the alleged cyberattacks.

A spokesman for the Heritage Foundation said “we do not discuss the deliberations of private meetings at Heritage,” while a spokeswoman for the Hudson Institute did not respond to requests for comment.

The Ukrainian embassy in Washington also did not respond to requests for comment.

But in foreign policy circles in Washington and Kiev, the Tymoshenko-Trump meeting was the subject of intense debate for its possible signals about Trump’s policy towards Ukraine and Russia, and also for its potential ramifications on Ukrainian domestic politics.

In both capitals, the meeting was seen as a major coup for Tymoshenko and an embarrassment for Poroshenko. The Ukrainian president, whose approval ratings have been soft, has been working assiduously to secure his own meeting with Trump, and has publicly suggested that such a meeting was imminent.

“I was one of the first world leaders to whom President Trump called immediately after the election, and we had quite a promising conversation.” Poroshenko last month told Bloomberg TV in an interview on the sidelines of the World Economic Forum in Davos. “We agreed that immediately after inauguration, we agreed the date of my visit to Washington, D.C., and the agenda of our negotiations would be quite big.”

The Washington lobbying and consulting firm retained by a Poroshenko-linked group sought to minimize the Tymoshenko meeting.

“According to participants in the Prayer Breakfast, Ms. Tymoshenko waited for President Trump in a corridor next to the restroom in the hope of catching him for a moment for a handshake,” said Jeff Birnbaum, president of BGR Public Relations, which represents the National Reform Council of Ukraine. “No real meeting took place. The President shook hands with many people and apparently one of them was Ms. Tymoshenko.”

But two operatives briefed on the reaction from within the Poroshenko administration said the Ukrainian president’s allies, including his ambassador to the U.S., Valeriy Chaly, were apoplectic when they learned of Tymoshenko’s meeting.

One of the operatives, an American who has worked in Ukraine, called it a “vote of no confidence” from Trump for Poroshenko. The operative attributed Trump’s willingness to meet with Tymoshenko at least in part to efforts during the election by Ukrainian government officials to help Clinton and undermine Trump, which POLITICO revealed last month.

“That was probably an issue,” said the American operative, “but there are a lot of forces at play here.”

The other operative, a political consultant with connections to the Poroshenko administration, said “the administration is furious with the meeting.” The consultant said Poroshenko’s team intends to take the position that the meeting “wasn't important, and they will try to ignore it as much as possible.” But the consultant added that “diplomatically, it was a slap in the face. They're mad and don't know what to do, and what will come next.”

Indeed, it’s rare for a U.S. president to meet with a foreign opposition leader before meeting with the country’s head of state.

A political analyst familiar with the discussions in Kiev said Haley’s comments have calmed some fears about the Trump administration leaving Ukraine in the lurch, even as there’s still lingering confusion about precisely where Trump stands on the issue.

“People are very worried about Trump,” said the analyst. “They are making a very concerted effort to reach out to the new administration.”

Citing the possibility that Poroshenko might be able to meet with Pence on the sidelines of an upcoming security conference in Munich, the analyst said, “There's hope in Kiev that Pence will play the same role as [former Vice President Joe] Biden,” who was seen as an advocate for Ukraine inside the Obama administration.

But Hannah Thoburn, a Hudson Institute research fellow specializing in Russia and Ukraine, said it’s not difficult to imagine Trump and Tymoshenko developing their own rapport.

“They're both business people and they both have a flare for presentation,” said Thoburn, who wouldn’t comment on Tymoshenko’s visit to Hudson. “I can imagine her and Trump getting along well.”