Ukrainian President Petro Poroshenko, center, poses with European Commission President Jean-Claude Juncker, left, and European Council President Donald Tusk during an E.U.-Ukraine summit in Brussels on Nov. 24. (Stephanie Lecocq/Reuters)

Ukrainian President Petro Poroshenko on Thursday said he believed he still had U.S. support after the election of Donald Trump, despite the president-elect’s campaign pledge that he “would be looking into” recognizing Russia’s annexation of Ukraine’s Crimean Peninsula.

Poroshenko has been forced into a reversal, campaigning in Brussels on Thursday for the European Union to make sure the United States upholds its sanctions against Russia, which were instituted after the 2014 Crimean annexation and subsequent conflict in Ukraine’s east. Just weeks ago, it was the United States that was pressuring Europe to maintain unity on sanctions, which some European nations want to abandon.

Poroshenko and a senior E.U. leader said they were optimistic that the European Union would extend its sanctions before their expiration at the end of January. Poroshenko said that Ukraine still had bipartisan support in Washington, while European Council President Donald Tusk said that his post-election conversation about Ukraine with Trump was “at least promising,” compared with the president-elect’s campaign rhetoric.

Ukrainian officials, although privately concerned about possible changes in U.S. policy toward their country following Trump’s ascendance, have maintained an iron wall of optimism in public. Poroshenko said that Trump himself had raised “the question of Russian aggression, illegal annexation of Crimea” during their Nov. 15 conversation.

“Ukraine has strong bipartisan support in the United States Congress,” Poroshenko said. “We don’t expect any significant changes in this bipartisan support.”

But Tusk was more guarded in his assessment of Trump’s coming policy on Ukraine.

When Tusk raised the issue of Crimea, Trump was “calm and very general without details, but at least promising compared to some announcements during the campaign time,” Tusk said. 

He said the E.U. position on sanctions is “very clear”: They are still linked to the fulfillment of a peace plan for Ukraine known as the Minsk agreements that is far from being implemented. 

The 28 E.U. nations plan to extend sanctions against Russia, most likely before a Dec. 16 summit of European leaders, Tusk said.

But it remains unclear whether E.U. sanctions would be able to survive in their current form if Trump abandons or loosens U.S. sanctions. The European sanctions are currently expected to be extended six months, until the end of July. Already, some European countries, Italy foremost among them, have been pushing for sanctions to be eased. But sanctions proponents inside Europe have been able to point toward transatlantic unity as a reason to extend them.

Trump has said he will improve relations with Russian President Vladimir Putin and has prioritized fighting the Islamic State in Syria together with the Kremlin.

But he has not always been negative about Ukraine. In a speech he made by video link to a September 2015 conference of supporters of Kiev’s integration into the European Union, he said that “people here have to band together from other parts of Europe to help.”

According to a recent tax filing by the Trump Foundation, the foundation of Ukrainian steel magnate Victor Pinchuk, who underwrites the conference, donated $150,000 to Trump’s foundation after the appearance.

A spokesman for the conference said at the time of the speech that Trump was the only invited candidate to agree to speak.

Poroshenko’s government has been growing more unpopular domestically, as pessimism increases about the leader’s willingness and ability to combat the corruption that has long plagued the country.

Europe has also struggled to deliver its side of the bargain in a trade deal with Ukraine. Dutch voters in April rejected the trade deal in a referendum, casting the entire agreement into doubt. And a European pledge to award visa-free travel to Ukraine has been delayed amid internal disagreements over how visa requirements might be reimposed if needed.