MOSCOW — President Trump plans to meet President Vladimir V. Putin in Helsinki, Finland, on July 16 for one-on-one talks, the White House said on Thursday, a politically delicate meeting that will take place while the special counsel continues to investigate the Trump campaign’s possible ties to Russia.

It will be the first formal summit meeting for Mr. Trump and Mr. Putin, who have spoken together twice on the sidelines of annual gatherings of world leaders, and it will come at a particularly critical moment, with midterm elections looming in the United States.

“The two leaders will discuss relations between the United States and Russia, and a range of national security issues,” the White House said in a statement.

The Helsinki talks, which will come on the heels of a NATO summit meeting in Brussels on July 11 and 12, could exacerbate American relations with European allies even as it eases tensions with Russia.