United States President Donald Trump met with European Union officials in Brussels on Wednesday, ahead of attending his first NATO Summit, which he previously called an "obsolete" alliance.

The trip to the European country comes in the wake of the deadly attack in Manchester. During his meeting with Belgian Prime Minister Charles Michel after he arrived in Brussels, Trump said the countries will work together to defeat "various problems. Number one is terrorism."

On Thursday, Trump is expected to attend his first meeting at NATO, the decades-long partnership that has been rattled by the new U.S. president's wavering stance on honoring its bonds. Trump has openly mused about pulling out of the pact, declaring the military alliance "obsolete." He believed other countries were not paying their fair share and refused to commit to abiding by Article 5, in which member nations vow to come to each other's defense.

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E.U. leaders, however, are hoping talks with Trump will stress continuity in their relations after the early months of his administration increased fears that the trans-Atlantic friendship was on the wane.

Trump met with Donald Tusk, the president of the European Council, Jean-Claude Juncker, the president of the European Commission, and other officials at the E.U. headquarters Thursday morning.

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Tusk said he was not "100 percent sure" he an Trump have "a common position, a common opinion, about Russia." But he said that regarding Ukraine "it seems that we were on the same line."



Tusk also said "some issues remain open like climate and trade," where the E.U. is pushing for full respect of the Paris Agreement on climate and open multilateral trade deals.

Brussels is Trump's fourth stop on his first foreign trip overseas since taking office. After attending the NATO summit, he will make his fifth and final stop in Sicily for the G7 summit on Friday.

The Associated Press contributed to this report.