This May 9, 2019 picture shows DPRK top leader Kim Jong-un attending the strike drill of defense units of the Korean People's Army (KPA) in the forefront area and on the western front of the DPRK. (KCNA VIA KNS / AFP)

SEOUL, ROK — The militaries of the US and the Republic of Korea (ROK) evaluated the two projectiles the Democratic People's Republic of Korea (DPRK) flew Thursday as short-range missiles, a military official of the ROK said Friday, a day after Pyongyang's second launch in five days raised jitters about an unraveling detente between the Koreas and the future of US-DPRK nuclear negotiations.

The launch raised jitters about an unravelling detente between the Koreas and the future of nuclear negotiations between Washington and Pyongyang

The weapons flew 420 kilometers and 270 kilometers, respectively, on an apogee of 45 to 50 kilometers, according to Seoul's Joint Chiefs of Staff and Defense Ministry. The launches were seen as Pyongyang's brushback pitch toward Washington over deadlocked nuclear negotiations as they continue to struggle with mismatched demands in sanctions relief and disarmament.

DPRK's state-run media Korean Central News Agency said Friday that leader Kim Jong-un helped guide the weapons tests on Thursday and learned about "various long-range strike means," but the statement did not specify the type of missiles fired.

Pyongyang's official Rodong Sinmun newspaper published photos that showed Kim, equipped with binoculars and smiling widely, observing the firing of rocket artillery and what appeared to be a short-range ballistic missile fired from a launch vehicle.

The National Intelligence Service of the ROK told lawmakers in a closed-door briefing on Friday that the missile is possibly part of a new weapons system of the DPRK, lawmaker Kim Min-ki said.

Experts said the missile was identical to the one the DPRK launched on Saturday, which appeared to be a solid-fuel missile modeled after Russia's Iskander short-range ballistic missile system. The Rodong Sinmun photos showed the DPRK used a tracked launch vehicle on Thursday, unlike Saturday when it used a wheeled vehicle.

This May 9, 2019 picture shows a rocket firing during the strike drill of defence units of the Korean People's Army (KPA) in the forefront area and on the western front of DPRK. (KCNA VIA KNS / AFP)

Some analysts say the new missile is potentially capable of delivering warheads and striking targets within the entire Korean Peninsula. It's unclear how closely the missile matches the capabilities of the Iskander, which can be maneuvered during flight to improve its chances of evading missile defense systems.

The military official from ROK said the ROK and US militaries are jointly analyzing more details from the launch, including whether the missiles fired on Thursday were the same weapons the DPRK tested on Saturday. He didn't want to be named, citing office rules.

What was launched Thursday is a crucial detail, as DPRK is banned by the United Nations from testing ballistic missiles. A major missile test could result in more sanctions, and the so far unsuccessful push for large-scale sanctions relief from DPRK is at the heart of the current diplomatic impasse with Washington.

ROK's military initially said Thursday that at least one projectile was launched from the Sino-ri area of North Pyongan province, an area known to have one of DPRK's oldest missile bases where a brigade operates mid-range Rodong missiles. It later said there were two launches from the nearby town of Kusong, where the DPRK conducted its first successful flight tests of its Hwasong-12 intermediate-range missile and Hwasong-14 intercontinental ballistic missile, both in 2017.

The ROK's unification ministry in charge of inter-Korean relations said on Friday that there was no change in its stance that it would be necessary to provide food assistance for the DPRK from the humanitarian and philanthropic perspectives

Kusong is also home to missile test facilities that were critical to the development of DPRK's solid-fuel Pukguksong-2, which was successfully flight-tested for the first time in February 2017, in DPRK's first missile test after President Donald Trump took office.

The latest launches came as US Special Representative for the DPRK Stephen Biegun visited ROK, and hours after the DPRK described its firing of rocket artillery and an apparent short-range ballistic missile on Saturday as a regular and defensive military exercise. The DPRK also ridiculed ROK for criticizing those launches.

Trump told reporters the weapons were smaller, short-range missiles, but: "Nobody's happy about it." He has met with Kim at two summits but said Thursday at the White House: "I don't think they're ready to negotiate."

ALSO READ: DPRK's Kim oversees 'strike drill' of rocket launchers

Moon Jae-in, president of the ROK, urged DPRK to refrain from actions that could impede diplomacy. In an interview with the KBS television network, Moon also said Seoul will explore various options to help revive the talks, including providing food aid to the DPRK and pushing for his fourth summit with Kim.

Moon's office earlier said the DPRK's launches were "very concerning" and detrimental to efforts to improve inter-Korean ties and ease military tensions on the Korean Peninsula.

Despite the latest launches, the ROK's unification ministry in charge of inter-Korean relations said that there was no change in its stance that it would be necessary to provide food assistance for the DPRK from the humanitarian and philanthropic perspectives.

Japanese Defense Minister Takeshi Iwaya said Friday that Tokyo finds it "extremely regrettable" that the DPRK fired short-range ballistic missiles in violation of UN Security Council resolutions. He said none of the missiles reached Japanese territory and there was no immediate impact on Japan's security.

Some analysts have said that if DPRK resumes testing the kind of longer-range banned ballistic weapons that it fired in unusually large numbers in 2017 — when many feared a US-DPRK standoff could end in war — it may signal that the DPRK is turning away from diplomacy.

The tensions in 2017 were followed by a surprising diplomatic outreach by DPRK in 2018, when Kim attended summits with the presidents of ROK, China and the US. But DPRK has not received what it wants most from its summitry: relief from punitive sanctions imposed over its nuclear and missile programs.

This May 9, 2019 picture shows rocket launchers firing during the strike drill of defence units of the Korean People's Army (KPA) in the forefront area and on the western front of the DPRK. (KCNA VIA KNS / AFP)

READ MORE: DPRK: Recent rocket drill was regular and in self-defense

In Geneva on Thursday, DPRK's Ambassador Han Tae Song likened the economic sanctions to "crimes."

With the consecutive weapons launches, DPRK is pressuring ROK to turn away from the United States and support DPRK's position more strongly, said Du Hyeogn Cha, a visiting scholar at Seoul's Asan Institute for Policy Studies. Following the collapse of the Trump-Kim meeting, DPRK demanded that the ROK proceed with joint economic projects that have been held back by US-led sanctions against the DPRK.

By firing weapons that directly threaten ROK but not the US mainland or its Pacific territories, the DPRK also appears to be testing how far Washington will tolerate its bellicosity without actually causing the nuclear negotiations to collapse, Cha said.

US Special Representative for the DPRK Stephen Biegun, right, talks with Kim Yeon-chul, unification minister of the ROK, during a meeting at the government complex in Seoul, ROK, May 10, 2019. (AHN YOUNG-JOON / AP)

"To the United States, the North is saying 'don't push me into a corner.' To South Korea, the North is saying the inter-Korean peace agreements could become nothing if Seoul fails to coax major concessions from the United States on behalf of the North," Cha said. The ROK is also referred to as South Korea and DPRK as North Korea. 

(With Xinhua input)