U.S. Sen. Brian Schatz, D-Hawaii, is among a group of lawmakers who have introduced a bill that would prohibit the president from starting a preemptive war against North Korea.
The bill says a preemptive war should only be allowed if there's an imminent threat or if the president has Congressional authorization.
"It is true that the Department of Defense never takes anything off the table," said Schatz, D-Hawaii.
"But we have to understand how catastrophic military action would be and we want to reinforce that message that we have a three-prong approach as a country -- they call it coercive diplomacy -- it's readiness, it's diplomacy and it's sanctions. We want to emphasize diplomacy because that is everybody's first choice."
The bill comes amid rising tensions with North Korea.
It would prohibit funds from being used for military operations without Congressional approval unless the United States faces an imminent threat or such action is necessary to defend citizens or our allies.