President Donald Trump's hawkish national security adviser, John Bolton, infuriated North Korea with a strange and threatening comment about denuclearization in May, and now he seems excluded from the talks.

Secretary of State Mike Pompeo has called Bolton's presence at North Korea talks "counterproductive" and angrily confronted him, according to CNN.

Experts now believe Bolton is trying to sabotage the talks.

President Donald Trump's hawkish national security adviser, John Bolton, infuriated North Korea with a strange and threatening comment about denuclearization in May, and now he seems excluded from the countries' talks.

When Trump met with the North Korean official Kim Yong Chol in the White House recently, only Secretary of State Mike Pompeo attended. Bolton, who has plenty to say about North Korea, did not.

The reason most likely goes back to Bolton's comment in May that the US was looking at a "Libya model" for denuclearizing North Korea.

The Libyan leader Muammar Gaddafi was killed by rebels in 2011 during a conflict in which the US intervened a few years after Libya dismantled its nuclear program. Bolton's comment was widely understood to imply that North Korean leader Kim Jong Un too would soon meet his end.

North Korea responded shortly after by lashing out at Bolton, saying it could not hide its anger toward him.

Now, Pompeo has told Trump that allowing Bolton to meet with North Korean officials would be "counterproductive," according to CNN.

"There has been considerable tension between them ever since" the two men clashed over Bolton's Libya comment, CNN quoted a source as saying.

Summit sabotage?

Bolton has never expressed much hope for a summit between Trump and Kim Jong Un, and now a growing chorus of experts think he may have tried to sabotage the summit.

North Korea and Libya are very different places, with different weapons programs and systems, and Bolton most likely would have known that bringing up Libya would anger Pyongyang.

Bolton, who has signaled that he does not trust the North Korean leader, is sensitive to perceptions that the US is wasting time with unproductive diplomacy.

As it stands, it's still unclear what will come from a scheduled June 12 meeting between the US and North Korean leaders.