Since July 25, the North has launched a series of short-range projectiles, including ballistic missiles, five times to protest the ongoing South Korea-US combined military exercise, which it sees as a rehearsal for an invasion.
"The latest test of a missile we denominate the KN 23, we think the range could probably hit all of South Korea and parts of Japan.
That of course would endanger our deployed forces as well," Bolton said in an interview with the VOA on Wednesday.
The KN 23 is seen as the North Korean version of Russia's Iskander surface-to-surface missile with a range of around 500 kilometers.
Bolton said that though the North's short-range missile tests contravene the UN resolutions, they don't break the pledge North Korean leader Kim Jong-un made with US President Donald Trump -- an indication that Washington still wants to keep dialogue open with Pyongyang.
The US maintains that the pledge the North Korean leader has made to Trump involves a moratorium only on intermediate-range and intercontinental ballistic missiles, not short-range ones.
Touching on the prospects of dialogue with the North, Bolton expressed hope that working-level talks would "begin again soon."
"We haven't had really any substantive negotiations, at the working level with North Korea since the president met with Kim Jong-un at the Demilitarized Zone between North and South Korea," he said.
Bolton then said the real issue is whether the North will make the "clear strategic decision to give up its nuclear weapons and its delivery systems." (Yonhap)