BERLIN — President Barack Obama is stressing a message of solidarity and trans-Atlantic cooperation on his final visit Thursday to Germany — a top trade partner, key NATO ally and home to thousands of American troops, as well as a nation critical to solving Europe’s migrant crisis and debt woes.

Obama arrived Wednesday night in Berlin from Greece, making his sixth and final visit as president to Germany, where he has been popular since even before he was elected. His eight years in office have helped erase much of the anti-American sentiment that had grown during the administration of George W. Bush over the Iraq war and other policies.

German Chancellor Angela Merkel, who worked well with Bush before Obama’s election, dined with Obama Wednesday night at his hotel and was to hold talks with him Thursday afternoon. The downtown area around the Chancellery and hotel where Obama was staying was locked down tightly, with some 2,400 police officers on hand manning road blocks and checkpoints.

In a joint opinion piece published Thursday in Germany’s weekly business magazine Wirtschaftwoche, which seemed directed as much at the incoming Trump administration in the U.S. as European nations, the two leaders stressed that the “underlying bedrock of our shared values is strong” even if the pursuit of common goals is sometimes gone about differently.

Obama and Merkel noted that European Union-US trade was the largest between any two partners worldwide, and emphasized that the trans-Atlantic friendship has helped forge a climate accord, provide help for refugees worldwide, form a collective defense under NATO, and strengthen the global fight against the Islamic State extremist group.

“That friendship is based on our shared commitment to personal freedom and dignity, which only a vibrant democracy under the rule of law can guarantee,” the leaders wrote.