President Donald Trump's nominee for ambassador to South Korea on Thursday backed the idea of a "pause" in major military exercises with South Korea, while talks on the North's nuclear program continue.

"The whole landscape has shifted, and I believe that we should give exercises, major exercises, a pause to see if (North Korean leader) Kim Jong Un is in fact serious about his part in negotiations," retired Adm. Harry Harris, who just stepped down as head of the U.S. military's Pacific Command, told a Senate hearing.

Immediately after his historic summit in Singapore with Kim last Tuesday, Trump announced he will halt U.S.-South Korea military exercises, a move long sought by North Korea.