The former chief of the U.S. Pacific Command won unanimous approval from the Senate Foreign Relations Committee ahead of a full Senate vote expected for early July.
New satellite images show North Korea has made rapid improvements to the infrastructure at its Yongbyon Nuclear Scientific Research Center - a facility used to produce weapons-grade fissile material, according to an analysis published by 38 North, a prominent North Korea monitoring group.
When news first broke earlier this year that Harris would be nominated for the post in Seoul, South Korean media described him as a hawk on North Korea, taking cue from his remarks during a 2014 Senate confirmation hearing for his admiral post that the North was America's "most volatile and risky threat".
Secretary of State Mike Pompeo has said the US will regularly assesses Pyongyang's seriousness toward abandoning its nuclear weapons program, but has not committed to a timeline or roadmap.
"Mike Pompeo: I don't want to get into the details of intelligence, but I think we have publicly said before that they have a breakup capacity that is in a number of months - 12 months to be precise". Survival is highly dependent on China, and sanctions to counter North Korea's nuclear threat have put further pressure on the economy. "I don't think there's any doubt about that".
Shortly after the summit with Kim, Trump declared that there was "no longer a Nuclear Threat from North Korea".
But Harris has since toned down his rhetoric in cue with the Trump administration's engagement with the North on denuclearization talks. "For the moment, we have reduced risk".
Pompeo said he would be leading the ongoing talks with Pyongyang, but declined to discuss details.
The line was cut again in November 2008 due to political tensions over North Korea's nuclear program and the hard-line policies of a new conservative government in Seoul. The peninsula remains in a technical state of war after the 1950-53 Korean War ended in an armistice, not a peace treaty.
However, that being said, North Korea remains tiny and backward.
"We should remain skeptical that North Korea's nuclear calculus has changed dramatically".