President Donald Trump’s increasingly tense relationship with Pyongyang has rattled members of Congress to such a degree that three Democratic senators announced a bill on Wednesday that would prohibit Trump from striking North Korea ― with nuclear or conventional weapons ― without obtaining congressional approval first.

Sen. Chis Murphy (D-Conn.) tweeted a series of messages about the proposed legislation, which he is introducing with Sens. Brian Schatz (D-Hawaii) and Cory Booker (D-N.J.).

″My bill … makes clear that any unauthorized preemptive strike on N Korea – nuclear or conventional – is illegal,” Murphy wrote.