South Korea’s military reiterated Friday that more time was needed to determine whether the short-range missiles the North fired the day before were ballistic missiles, while the United States announced that they were.

Seoul’s Joint Chiefs of Staff told reporters that South Korea and the US jointly deemed the two projectiles to have been short-range missiles, and that further analysis would be needed to determine the exact nature of the missiles.

In a statement Thursday, Pentagon spokesman Lt. Col. Dave Eastburn said the North “flight-tested multiple ballistic missiles” and they flew to distances “in excess of 300 km before impacting in the ocean.”

The statement followed a JSC announcement indicating that North Korea fired two short-range missiles at 4:29 p.m. and 4:49 p.m. from Kusong, North Pyongan Province, Thursday. It was the second instance of military action by North Korea within a week. Previously, on May 4, the North fired multiple projectiles into the East Sea from the east coast town of Wonsan.

If the projectiles are confirmed to be ballistic missiles, the incident is likely to aggravate the impasse in nuclear negotiations, as the North is banned from launching any ballistic missiles under UN Security Council resolutions.

Rep. Ahn Gyu-back, the head of the South’s parliamentary defense committee, raised concerns that the recent launches are highly likely to have violated the UN resolutions.

“But there still needs to be detailed analysis, as the altitude where the launches took place is low,” Rep. Ahn told reporters after his meeting with the JSC on Friday.

The projectiles fired Thursday appear to be the same as the ones launched May 4, which the North had referred to as a new “tactical guided weapon.”

But the transporter erector launchers used on the two occasions were different, a military official here explained.

“Differences are found in the appearance of the launches. (Pyongyang) used a TEL vehicle with wheels on May 4, but a tracked vehicle was used for Thursday’s test,” the official said. “We are currently analyzing the flying characteristics.”

Experts and military officials here believe the short-range missiles the North launch may be the North Korean version of the “Iskander,” a Russian tactical ballistic missile.

The two short-range missiles launched Thursday flew eastward at an altitude of between 40 and 50 kilometers and landed in the East Sea. They flew 420 kilometers and 270 kilometers, respectively.

The Iskander is a solid-fueled missile system with two variants -- one for use by Russia’s armed forces, and one for export. The domestic version has a range of 400 kilometers, while the export version, called the “Iskander-E,” has a range of 280 kilometers. It is thought that North Korea may have upgraded the export version.

“The range and altitude of the missiles are similar to those of the Iskander, and so is its appearance,” a military official said on condition of anonymity.

The second launch happened just as the South Korean government was ramping up efforts to send food aid to North Korea, and seeking the resumption of nuclear negotiations that had been toppled after US President Donald Trump and North Korean leader Kim Jong-un’s summit ended without an agreement in February.

A military official also hinted that the recent military actions may have been undertaken for internal consolidation, and that the Kim regime might be facing opposition within the country.

By Jo He-rim (herim@heraldcorp.com)