But the episode underscored that Mr. Trump obtains, processes and uses information differently from any modern president. He watches television at night and tends to incorporate what he sees into his Twitter feed, speeches and interviews.

“It begs the question of where the president gets his information as he articulates his administration’s global approach,” said Mark Brzezinski, the ambassador to Sweden under President Barack Obama. “To do so in an improvisational way, based on snippets picked up from cable news, is a major mistake.”

Immigration is a hotly debated issue in Sweden, Germany and many other European countries. Sweden, which prides itself as a humanitarian leader, processed a record 163,000 asylum applications in 2015. But statistics in Sweden do not back up the suggestion that immigrants have created a major crime wave.

Preliminary data released last month by Sweden’s crime prevention council found no significant increase in crimes from 2015 to 2016, even with the influx of migrants. The council did note an increase in assaults and rapes last year, but it also recorded a drop in thefts and drug offenses. Still, a Pew Research Center survey last year found that 46 percent of Swedes said refugees were more to blame for crime than other groups.

Manne Gerell, a doctoral student in criminology at Malmo University in Sweden, said in an interview that immigrants were disproportionately represented among crime suspects, particularly in more serious and violent offenses. But he noted that many of the victims were other immigrants, whether members of criminal networks or simply residents of poor neighborhoods.

“Immigration will come with some cost, and we will likely have a bit more crime — but that’s in a society with low crime rates and in a society that works really well, so in my opinion, it’s something we can live with,” he said. “I know everybody won’t agree with that. But immigration will not double the crime rate, make everybody go broke or turn Sweden into a living hell.”

Although terrorism is a concern for Sweden — an Iraqi-born Swede blew himself up in central Stockholm in 2010 — the authorities say they are equally worried about racist hate crimes, including attacks on migrants.