Financial records filed last year in the secretive tax haven of Cyprus, where Paul J. Manafort kept bank accounts during his years working in Ukraine and investing with a Russian oligarch, indicate that he had been in debt to pro-Russia interests by as much as $17 million before he joined Donald J. Trump’s presidential campaign in March 2016.

Describing a newly disclosed informal conversation he had with President Vladimir V. Putin of Russia during a dinner of world leaders in Germany earlier this month, Mr. Trump said they talked for about 15 minutes, mostly about “pleasantries.” But Mr. Trump did say that they talked “about adoptions.” Mr. Putin banned American adoptions of Russian children in 2012 after the United States enacted sanctions on Russians accused of human rights abuses, an issue that remains a sore point in relations with Moscow.

Mr. Trump acknowledged that it was “interesting” that adoptions came up since his son, Donald Trump Jr., said that was the topic of a meeting he had with several Russians with ties to the Kremlin during last year’s campaign. Even though emails show that the session had been set up to pass along incriminating information about Hillary Clinton