Worried over what they described as President Trump’s erratic response to North Korea’s behavior, 64 Democratic legislators urged him on Tuesday to talk directly to the North Koreans — and warned that he would need congressional approval for any pre-emptive military strike.

“Few decisions are more needing of debate than a move to launch attacks, or declare war, on a nuclear-armed state such as North Korea,” read a letter signed by the lawmakers, led by Representative John Conyers Jr. of Michigan, the last Democrat in Congress to have served in the 1950-53 Korean War. “In such a volatile region, an inconsistent or unpredictable policy runs the risk of unimaginable conflict.”