North Korea over the weekend conducted a test of a rocket engine, South Korea’s defense minister said on Tuesday, expressing “deep concern” regarding Pyongyang’s recent steps and calling on the DPRK to stop heightening military tensions.

Speaking during a press conference in Sydney alongside top officials from both South Korea and Australia, minister Jeong Kyeong-doo condemned the DPRK’s “continued launching of ballistic missiles and the engine-testing activity at the North’s Sohae… area.”

This is apparently the first time that a high-level South Korean government authority had confirmed that North Korea’s recent test — which Pyongyang has simply described having been “very important” and “changing the strategic position of the DPRK” — was of a rocket engine.

North Korea is yet to reveal further details of the weekend’s test.

Writing for NK News‘s sister site NK Pro earlier this week, Ankit Panda, an adjunct senior fellow at the Federation of American Scientists, argued the test had likely been of a rocket engine.

Jeffrey Lewis, a WMD analyst at the James Martin Center for Nonproliferation Studies (CNS), also noted Monday that satellite imagery suggested North Korea conducted “a rocket engine test” at the Sohae Satellite Launching Center.

Seoul’s defense minister on Tuesday, explicitly referring to North Korea’s recent test as an “engine test activity,” added that the respective defense ministers of Sydney and Seoul “strongly urge the North to… immediately stop the activity that raises military tension.”

North Korea last conducted a rocket engine test in March 2017, and with the country’s self-declared end-of-year deadline and a key ruling party plenum approaching, North Korea has stepped up hints that it may be preparing a return to the kinds of regular provocative military actions seen that year.

In a statement Monday, Kim Yong Chol, a senior official on the DPRK ruling party’s Central Committee, warned the country now has “nothing to lose,” and promised a looming “surprise” for U.S. President Donald Trump.

Speaking to NK News on Tuesday, analyst Ankit Panda said that despite emerging evidence in the open source intelligence (OSINT) community and the South Korean government of an engine test at Sohae, North Korea may be seeking to retain the “element of surprise” by keeping the details secret.

“As Kim Yong Chol told us, they want an element of surprise — to really showcase their qualitative advancements over the last two years,” he said.

“They want to really give the United States a wake-up call,” he explained. “A solid fuel ICBM, or even something like multiple warheads, out of the blue would do that. No need to tease us with more detail than necessary about an engine test.”

North Korea’s low-profile testing also represents a recent trend, Panda noted.

“In general, we notice a trend away from the radical transparency around testing activities seen during the byungjin testing campaigns.”

Edited by Oliver Hotham

Featured image: Rodong Sinmun