The Ministry of Unification said that the North made a "rare" direct condemnation of China, given that previously Pyongyang used the term "a neighboring country" when criticizing Beijing.

"North Korea seemed to show a strong reaction as China has joined other nations' move to send a message against its nuclear and missile provocations," said a ministry official, asking not to be named. "Pyongyang needs to pay attention to this message."

The official also added that North Korea appeared to adjust its level of criticism by using what appears to be the pen name of Kim Chol.

China is North Korea's key economic benefactor and treaty ally, but their ties have been frayed following North Korea's nuclear and missile tests.

In February, North Korea condemned China over its decision to halt imports of North Korean coal, saying that Beijing is "dancing to the tune of the US," referring to China's implementation of the UN sanctions.

At that time, the KCNA said that a neighboring country that often claims itself to be a "friendly neighbor" is showing an unkind attitude toward North Korea, apparently referring to China.

China has sought a dual-track approach toward North Korea's problems, saying that peace treaty talks between the North and the US should be proceeded in tandem with negotiations on denuclearization.

North Korea on Wednesday reiterated its stance of sticking to nuclear weapons development, a slap in the face for China.

Meanwhile, US President Donald Trump said in an interview with Bloomberg News on Monday that he would "absolutely" be willing and "honored" to meet with the North's leader Kim if such a meeting takes place "under the right circumstances."

Pyongyang fired a missile last week, but it seems to refrain from conducting another nuclear test or launching an intercontinental ballistic missile, an act that would be certain to anger the US.

Cheong Seong-chang, a senior research fellow at the Sejong Institute, said that North Korea showed strong complaints over China's cooperation with the US in employing sanctions against the North.

"North Korea is expected to try to strengthen its ties with Russia while seeking to intentionally ignore China. If a new administration takes office in South Korea, Pyongyang. (Yonhap)