Dan Smith of the Stockholm International Peace Research Institute suggested nuclear weapon development was continuing despite rapprochement with the U.S.
Pyongyang has conducted seven rounds of short-range missile tests since July with denuclearization talks with the U.S. in limbo.
Victor Cha was nominated to become Trump's ambassador to South Korea but was dropped after warning the White House against a pre-emptive strike on the North.
"It's not a stretch to say that Donald Trump's most lasting legacy may well be writing what he calls love letters to a dictator in North Korea," Joe Scarborough said.
South Korean media reported early Saturday that North Korea launched two short-range ballistic missiles into the sea, the country's latest act of defiance in protest of the drills, which the country has always objected to.
Two short-range ballistic missiles were launched on Wednesday in North Korea's second such test in less than a week.
Kim Dong Chul was one of three American citizens released from North Korean prisons and returned to the U.S. in 2018.
The latest test is sure to increase tensions as Pyongyang and Washington attempt to restart talks on denuclearization and sanctions relief.
Reports suggested the new submarine may have been designed to carry and launch ballistic missiles, which could in future be tipped with nuclear warheads.
Pictures were hung up of leaders that President Donald Trump has met so far this year.
The correlation between the 40th and 45th U.S. presidents, especially on foreign policy, is deliberate and systematic, not simply coincidental.
"President Obama was handed the Nobel Peace Prize, but President Trump is on his way to actually earning one," Conway said.
Cooper's segment, titled "There's something about a dictator," detailed the president's concerning rapport with the world's most controversial leaders.
He may have "obesity hypoventilation syndrome, which is a fancy word for someone who is obese and can't get enough air into their lungs and has a thick neck with fat in the neck that suppresses breathing," Fox News medical contributor Dr. Marc Siegel said.
"He has not curbed his use of nuclear weapons and missiles as he said he would," former U.S. ambassador to the UN Bill Richardson said.
Love letters between the leaders won't end seven decades of war, and the sides are running out of time.
The Chinese premier's work was vital in enabling Trump and Kim Jong Un to meet at the border of the two Koreas on Sunday, an editorial argued.
"What have we gotten from the North Koreans, for all this pomp and circumstance and the propaganda coup of having the president of the United States crossing into North Korea?" Elise Jordan asked.
Trump became the first U.S. president to set foot in North Korea on Sunday when he crossed the border with Kim.
"I mean, [Kim] was lobbing missiles into the Sea of Japan just a few weeks ago and the president is going to talk to him? I mean, are you kidding me?" Rep. Tim Ryan (D-Ohio) said.
"Not on the scale that the North Koreans do, but a lot of countries commit atrocities, including a number that we're closely allied with," Tucker Carlson said.
"Trump endorsing American citizen Otto Warmbier's murderer. Again," wrote a former federal prosecutor.
"That's news to me," said James Clapper.
Some interpreted the step as a watershed moment in denuclearization. Critics, meanwhile, blasted the president for his friendly demeanor toward the dictator.
"When you talk about a border, that's what they call a border," Trump said. "Nobody goes to that border, just about nobody. That's called a real border."
Author Anna Fifield's new book provides fresh details on the dictator-to-be's adolescent years growing up in the picturesque Swiss capital of Bern.
Relations between Washington and Pyongyang look far less promising than they did one year ago, with denuclearization negotiations stalled since the collapse of the Hanoi summit.
Kim Jong Nam was assassinated with a nerve agent in February 2017, reportedly after having met with his CIA contact in Malaysia.
The new book depicts the young Kim as an intelligent, confident but isolated child as he grew to become heir apparent to the secretive kingdom.
The North Korean foreign ministry demanded the U.S. abandon its "current way of calculation" if it wished to revive bilateral talks.