U.S. National Security Adviser John Bolton said the U.S. needs more evidence that North Korean leader Kim Jong-un is ready to give up his nuclear weapons before a third summit with U.S. President Donald Trump.

Bolton made the remarks on Wednesday during an interview with Bloomberg News when asked what the U.S. would need to see ahead of a third meeting between Trump and Kim.

Bolton said he thinks a "real indication" from North Korea that they've made the strategic decision to give up nuclear weapons would be needed. He added President Trump is fully prepared to have a third summit if he can get a real deal.

When asked if there had been any progress towards denuclearization, Bolton responded that he wouldn’t say the U.S. could say that at this point. 

Bloomberg said that Bolton's remarks struck a more pessimistic tone than other members of the administration, including Secretary of State Mike Pompeo, regarding North Korea’s intentions and the prospects for a deal.