Many U.S. colleges and universities, seeing declining numbers of applications from overseas, are trying to reassure potential international students they will be welcome on campus despite what they see in the news.

Schools are ramping up marketing efforts geared toward foreign students to combat growing fears that President Donald Trump's stance on immigration reflects a United States that is becoming less welcoming to foreigners.

Nearly half the nation's 25 largest public universities saw undergraduate applications from abroad fall or stagnate since last year, according to data colleges provi...