"There are no quick, surgical military solutions to the North Korea threat, and this is no time for reckless, provocative tweets," Leahy said. "This is a global challenge and the response must be a collective one."
Leahy added that the sanctions passed on Saturday by the UN Security Council should be used as leverage while diplomatic options are explored.
On Tuesday, President Donald Trump warned North Korea not to make any more threats against the United States or Pyongyang will face "fire and fury" like the world has never seen.
Trump’s statement came as media reported US intelligence has assessed that North Korea has produced a miniaturized nuclear warhead.