North Korea appeared to lash out at Beijing in a state-media commentary published on Thursday, in unusually pointed rhetoric from Pyongyang toward a powerful neighbor that it has long relied on for economic support.

The commentary, published by the state-controlled Korean Central News Agency, didn't name China, but left little doubt about its target: "a neighboring country, which often claims itself to be a 'friendly neighbor'."

In particular, the article lambasted China for playing down North Korea's nuclear capabilities, and for curbing foreign trade—an apparent reference to China's statement over the weekend that it would suspend coal imports from North Korea for the rest of the year.

North Korea remains heavily reliant on its larger neighbor for trade, while China sees North Korea as a buffer against South Korea and Japan, both U.S. allies. But Beijing's patience wore thin after Pyongyang conducted a series of nuclear and ballistic-missile tests last year, prompting China to back fresh United Nations sanctions in November that target North Korea's coal exports.

According to the KCNA report, the unnamed country "has unhesitatingly taken inhumane steps such as totally blocking foreign trade related to the improvement of people's living standard under the plea of the U.N. 'resolutions on sanctions' devoid of legal ground."