"It looks like it's a testing series, that they want this missile fully operational. If they appear to be ballistic missiles, the president and Kim Jong Un have an understanding that Kim Jong Un is not going to launch longer-range, intercontinental-range ballistic missiles," Bolton told Fox News.
Earlier in the day, the South Korean Joint Chiefs of Staff said that North Korea had twice launched unidentified projectiles into the Sea of Japan.
Bolton stressed that Trump is watching North Korea's tests "very carefully."
Japanese Defence Minister Takeshi Iwaya said during a press conference that the new launches of projectiles by North Korea were "a serious threat and a significant challenge for the country."
North Korea has already conducted three short-range missile tests within less than two weeks: on 25 July, on 31 July and last Friday.
The situation on the Korean Peninsula significantly improved last year after North Korean leader Kim Jong Un’s talks with South Korean President Moon Jae-in and US President Donald Trump. In June 2018, Kim and Trump reached an agreement, stipulating that North Korea would make efforts to promote complete denuclearization of the peninsula in exchange for US-South Korean military drills' freeze and potential removal of US sanctions. However, the negotiating process stalled earlier this year, with tensions escalating after Pyongyang’s missile tests.