President Donald Trump's upcoming meeting with North Korean strongman Kim Jong Un could be "extremely dangerous" and could "go very wrong," says John Dean, the attorney who served as White House Counsel for President Richard Nixon.

Dean took to Twitter on Friday morning to warn that the powwow cannot be considered anything like Nixon's historic 1972 trip to China to meet with Chairman Mao Zedong and Premier Zhou Enlai.

This is not a "Nixon to China" moment. Trump is playing way out of his league and the world knows it. Kim knows it. Much can go very wrong and Trump won't read a briefing book. Going to be interesting— and extremely dangerous. Kim will give him a parade and have his mind/heart. https://t.co/jmowg7ZDIn — John Dean (@JohnWDean) March 9, 2018

Trump announced Thursday that he was open to meeting Kim in what would be the first face-to-face encounter between any leaders of the two countries.

Kim Jong Un talked about denuclearization with the South Korean Representatives, not just a freeze. Also, no missile testing by North Korea during this period of time. Great progress being made but sanctions will remain until an agreement is reached. Meeting being planned! — Donald J. Trump (@realDonaldTrump) March 9, 2018

It was a stunning about-face from the months of name-calling the two engaged in as Kim mouthed off about North Korea's nuclear might and boasted his missiles could reach U.S. soil, while Trump said he had a "nuclear button" that was "much bigger" and "more powerful."

Kim referred to Trump as a "dotard" while the commander in chief ripped Kim as "Little Rocket Man."

Dean, who was a major figure in Nixon's Watergate scandal and pleaded guilty to obstruction of justice, has long been a vocal critical of the Trump administration. On Thursday, he criticized the president's approval of a controversial tax on imported steel and aluminum, tweeting: