Kim Jong Un's regime "has interpreted America's past restraint as weakness," he said. "This would be a fatal miscalculation. This is a very different administration than the United States has had in the past."
"Do not underestimate us, and do not try us," Trump warned, urging the pariah state to stop developing ballistic missiles and calling for it to dismantle its nuclear program.
"The weapons you are acquiring are not making you safer, they are putting your regime in grave danger," the U.S. leader said in remarks directed to Kim. "Every step you take down this dark path increases the peril you face."
Trump is the first U.S. president to address South Korea's parliament, known as the National Assembly, since Bill Clinton in 1993. The U.S. leader is on a landmark Asia tour and arrived in Seoul on Tuesday following a two-day stay in Japan. He is scheduled to depart for China later on Wednesday.