President Donald Trump speaks at a joint press conference with Poland's President Andrzej Duda in Warsaw, Poland, Thursday. The media event was Trump's first overseas news conference.

WARSAW, Poland — On the eve of his first meeting with Russian President Vladimir Putin, President Donald Trump vowed today to confront “new forms of aggression” targeting the West and called for Moscow to stop fomenting unrest around the world. Yet he pointedly stopped short of condemning Russia for meddling in the U.S. election.

Buoyed by an electrified crowd in Poland chanting his name, Trump sought to show he wasn’t overlooking Russian actions that have elicited global consternation, especially from nearby nations in eastern and central Europe.

He warned that Western interests were being tested by “propaganda, financial crimes and cyber warfare,” forcing NATO to adapt.

“We urge Russia to cease its destabilizing activities in Ukraine and elsewhere, and its support for hostile regimes including Syria and Iran, and to join the community of responsible nations in our fight against common enemies and in defense of civilization itself,” Trump said in a speech in Warsaw’s Krasinski Square.

It was a critique that the president did not appear to extend to Russia’s actions last year during the presidential campaign. In a news conference before his speech, Trump questioned the veracity of American intelligence about foreign meddling in the U.S. election, arguing that Russia wasn’t the only country that may have interfered. “Nobody really knows for sure,” he said.

Opening his second overseas trip as president, Trump also warned North Korea that he’s considering “some pretty severe things” in response to the isolated nation’s unprecedented launch of a missile capable of reaching the U.S. Though he declined to offer specifics on the U.S. response, Trump called on all nations to confront the North’s “very, very bad behavior.” He also stated unequivocally that the U.S. stands “firmly behind Article 5,” the NATO provision requiring the U.S. to defend other member nations if they come under attack. On his inaugural trip to Europe in May, Trump declined to affirm that commitment, to the dismay of U.S. allies who said it cast doubt on his allegiance to the alliance.

As U.S. investigations into Russia’s meddling forge ahead, Trump is under intense scrutiny for how he handles his first face-to-face session with Putin. U.S. intelligence officials say the unpredictable Russia leader ordered interference into the 2016 election.

Trump and Putin plan to sit down on Friday in Hamburg, Germany, on the sidelines of an international summit. Asked specifically whether he planned to discuss election meddling with Putin, Trump demurred.

Loath to cast a shadow on his election victory, Trump has avoided firmly blaming Moscow for campaign hacking. He said today that it could have been Russia, probably was Russia and indeed was Russia, while insisting it could have been other countries, too, and adding: “I won’t be specific.”

The president sought to redirect scrutiny toward his predecessor, Barack Obama, accusing him of allowing Moscow to meddle on his watch. Though the Obama administration warned Russia publicly and privately before Election Day to stop interfering, questions have since been raised about whether he acted aggressively enough to stop the threat.

“They say he choked. Well, I don’t think he choked,” Trump said. “I think he thought Hillary Clinton was going to win the election, and he said, ‘Let’s not do anything about it.’”

Using information collected by the FBI, CIA and National Security Agency, the U.S. national intelligence director last year concluded that Moscow was behind the hack of Democratic Party email systems and attempted to influence the 2016 election to benefit Trump.