The president’s approach has bent the norms of a protocol system put in place by Mr. Trump’s modern predecessors, according to Peter Selfridge, who served as the United States chief of protocol during the Obama administration.
“Obviously,” Mr. Selfridge said, “this president uses the press conference a little differently.”
President Barack Obama would regularly give his diplomatic guests warnings that a press availability might contain off-topic questions, according to a former Obama administration official who spoke on the condition of anonymity. But Mr. Obama would also appear visibly annoyed when asked questions not related to the purpose of the visit, especially if he was abroad.
When asked if Mr. Trump gave his visitors a similar heads-up, Stephanie Grisham, the White House press secretary, indicated that there was no need.
“I think foreign leaders are well aware that the U.S. press corps often has no desire to cover the foreign diplomacy taking place during these visits,” Ms. Grisham wrote in an email.
Indeed, Mr. Trump’s behavior often overshadows whatever diplomacy is taking place. White House officials told journalists before Mr. Niinisto’s visit that it would focus on economic cooperation and mutual security concerns between the two countries, which is a familiar refrain before any such visit.
But in the past two weeks, impeachment and the allegations against Mr. Trump and his relations with Ukraine have overshadowed diplomatic concerns.
That was more than just subtext to Mr. Trump’s meeting last week in New York with Volodymyr Zelensky, the Ukrainian president. Mr. Zelensky, who in a transcript of his phone call with Mr. Trump in July adeptly flattered the president, could barely mask his discomfort when the two met with reporters afterward.