WASHINGTON — President Trump insisted on Friday that there was nothing inappropriate about his administration’s dealings with Ukraine, playing down a series of texts between American diplomats and a Ukrainian official that were released Thursday night that outlined his attempt to tie a possible White House meeting and military aid to investigating former Vice President Joseph R. Biden Jr.

Mr. Trump homed in on a comment from Gordon D. Sondland, a major Republican fund-raiser whom Mr. Trump appointed as ambassador to the European Union, who in one of the texts defended the president’s intentions and said there were no “quid pro quos of any kind.”

“If you look, he also said there was no quid pro quo,” Mr. Trump said. “That’s the whole ballgame.”

But in another text released Thursday, his own ambassador in Ukraine, William B. Taylor Jr., said he suspected there was a quid pro quo. “As I said on the phone, I think it’s crazy to withhold security assistance for help with a political campaign,” he wrote Mr. Sondland on Sept. 9.

Mr. Trump made his comments the day after openly calling on China to also examine unfounded allegations against Mr. Biden and his younger son, Hunter Biden. The president’s request came only moments after he discussed upcoming trade talks with China and said that “if they don’t do what we want, we have tremendous power.”