During his campaign, Donald J. Trump vowed to end the Ukraine war by Day 1 of his new term as president. Jeanna Smialek, the Brussels bureau chief for The New York Times, looks at how he described the war in an appearance at the World Economic Forum since taking office.

On President Trump’s first day in office, he pulled out of the Paris Agreement, a pact among nearly all nations to fight climate change. Reporting from Davos, Switzerland, David Gelles, a climate journalist for The New York Times, explains what this decision means for the rest of the world.

President Trump doubled down on the prospect of across-the-board tariffs in a video appearance to business executives and politicians gathered in Davos, Switzerland.

C.E.O.s, policymakers and billionaires at the World Economic Forum’s conference have long pledged to fight climate change. Has it done any good?

Officials and business executives at the annual gathering in Switzerland said the fight against global climate change would continue with or without the United States.