The president-elect spoke to reporters briefly before a meeting with retired Lt Gen Michael Flynn, his incoming White House national security adviser.
Asked whether the attack was prompting him to reevaluate his call during the campaign for temporarily banning Muslim immigration into the United States, Trump said, "I've been proven to be right."
Twelve people were killed and 48 injured when a truck plowed into a popular Berlin market Monday evening in an attack claimed by the Islamic State group. German officials have launched a Europe-wide manhunt for a "violent and armed" Tunisian man suspected in the attack.
While Trump has assembled his Cabinet at a quick pace, the process to fill out top White House jobs has been slowed by pushback among some advisers.
More From This Section
Some of Trump's earliest advisers have expressed concern to the president-elect himself that they are getting boxed out in favor of those more closely aligned with incoming chief of staff Reince Priebus, who has chaired the Republican National Committee.
Trump won't be bringing his first campaign chief, Corey Lewandowski, into a White House job, but the combative operative won't be far away. Lewandowski said Wednesday he would not be joining the administration.
The president-elect's transition team has said announcements on White House staffing could come as early as Wednesday.