Meanwhile, Secretary of State Mike Pompeo on Wednesday expressed hope that stalled talks between the USA and North Korea aimed at lifting global sanctions on Pyongyang in exchange for denuclearization would soon resume. Pyongyang has also expressed anger over planned U.S.
The U.N. Security Council is expected to discuss the latest launches behind closed doors Thursday at the request of the United Kingdom, France and Germany, council diplomats said.
In a private briefing to lawmakers Wednesday, South Korean military intelligence officers said they've determined that the submarine likely has three launch tubes for missiles, according to Lee Hye-hoon, head of parliament's intelligence committee.
Pedestrians walk past a screen in Tokyo reporting about North Korea's test firing of a rocket system off the coast of North Korea on Wednesday.
US national security adviser John Bolton said on Wednesday North Korea's recent missile tests did not violate a pledge its leader Kim Jong Un made to President Donald Trump.
North Korean Foreign Minister Ri Yong Ho canceled a planned visit to this week's ASEAN forum, but Pompeo told reporters traveling with him the Americans were still open to a meeting and he hoped U.S. Special Representative for North Korea Stephen Biegun and his new North Korean counterpart could meet soon.
"You have to ask when the real diplomacy is going to begin, when the working-level discussions on denuclearization will begin", he told Fox Business. The North also tested short-range missiles on May 4 and 9.
South Korea says the Japanese trade curbs could hurt its export-dependent economy and has accused Japan of weaponizing trade to retaliate against South Korean court rulings calling for Japanese companies to compensate aging South Korean plaintiffs for forced labor during World War II.
North Korean leader Kim Jong Un called his recent weapons tests an important advance for the country's arsenal and a demonstration of power created to "send a solemn warning" to South Korea.
The missile is solid-fueled and launched from a truck, meaning it can be easily hidden and rapidly deployed.
"I think the KN-23 is flying low enough that it is hard for South Korea's radar to detect".
Trump, who now appears to have established a precedent for not complaining about North Korea's short-range missile tests, is in an awkward position. "It's going to mean some expensive upgrades to track these new missiles better, or the USA will have to use space based infrared and pass information very quickly to South Korea", says Melissa Hanham, a weapons expert with the Open Nuclear Network.
In November 2017 a North Korean soldier was shot multiple times by fellow soldiers as he fled across the border into South Korea, where he was treated by doctors. "Sending the message that there is a way for Kim to get what he wants but he can only do so via diplomacy and not missile tests", he adds.
A spiralling row over the past month is threatening to disrupt the global supply of semiconductors and undercut security cooperation on North Korea.
"These missiles represent technological developments that threaten USA allies and forces in Asia", he says.