BEIJING (Reuters) - China told an envoy of North Korean leader Kim Jong-un that Pyongyang should stop conducting nuclear and missile tests, but the North showed little sign of heeding the request, said a source with knowledge of the talks held late last month.
Kim dispatched Choe Ryong-hae, vice chairman of the country's top military body, to explain North Korea's recent actions but he got a lukewarm reception from his Chinese hosts, said the source, who has close ties to Beijing and Pyongyang.
North Korea's 30-year-old leader took power in December 2011 and has carried out two long-range rocket launches and a nuclear weapons test since then. He also embarked on a months-long campaign of threats against South Korea and the United States.
"(North) Korea has not mellowed," said the source, who did not attend the meetings but has since spoken to both sides to which he has regular access.
Choe, nominally a general but with no known military experience, is the Korean People's Army's top ideologue. He showed up in Beijing in full military regalia, in contrast to his suited Chinese counterparts.
Experts have said the three-day visit was an attempt by North Korea to mend fences with its only major diplomatic ally, which has been critical of Pyongyang.
After the meetings, in which Choe eventually held talks with Chinese President Xi Jinping, North Korea promised to take "positive steps for peace" while China repeated its mantra of wanting "calm and restraint" on the Korean peninsula.
Beijing tried to convince Pyongyang to stop its nuclear and missile tests, which "put China in a difficult position and are not conducive to (North) Korea", the source said. China advised North Korea to focus on rebuilding its ruined economy instead, something it has said before.
North Korea's recent actions drew international condemnation and put Beijing under pressure, especially from Washington, to rein in Pyongyang. It also helped reinforce an American strategy of rebalancing its security policies toward the Asia-Pacific.
China is North Korea's biggest trade partner and aid donor. Choe was shown a special enterprise zone during his visit, but he did not raise the issue of aid during his talks, the source added.
Asked if Pyongyang had agreed to halt nuclear tests, the source said that for the North: "It hinges on necessity."
North Korea has repeatedly said it will never abandon its nuclear weapons, calling them its "treasured sword".
The source did not say if Beijing spelt out any consequences should the North conduct further tests.
Choe met officials from the Chinese government, the military and ruling Communist Party.
China has grown increasingly frustrated with Pyongyang. It agreed to new U.N. sanctions after Pyongyang's latest nuclear test in February, and Chinese banks have curbed business with their North Korean counterparts in the wake of U.S. sanctions on the country's main foreign exchange bank.
A former senior U.S. official said Beijing's insistence that North Korea halt testing would be in line with recent signs it was running out of patience with Pyongyang.
"What I've heard from talking to Chinese officials and American officials who are talking to them is that top Chinese officials now emphasize that the principal goal is to terminate the nuclear weapons program of North Korea," the ex-official said.
"Usually, in the past that's been buried (by the Chinese)."
Choe presented a hand-written letter from Kim to Xi. Chinese media gave no details of its contents at the time, but the source close to Pyongyang and Beijing described it as "terse".
Kim stressed in his letter that "the traditional friendship created by the older generation of revolutionary leaders should not waver at any time", said the source.
China has backed North Korea since Mao Zedong sent Chinese troops to bolster Communist forces under then North Korean leader Kim Il-sung - Kim Jong-un's grandfather - during the 1950-53 Korean war.
The nuclear and rocket tests and verbal threats were partly aimed at forcing the United States and South Korea to sign a permanent peace treaty with North Korea to replace the armistice agreement that ended that conflict, the source said.
North Korea felt the reception Choe got was lukewarm, said the source. It was the most important visit to China by a North Korean delegation since the young Kim's uncle, a kingmaker among Pyongyang's ruling elite, visited Beijing in late 2012.
"There was no bear hug between Wang Jiarui and Choe when they met," the source noted, referring to the Chinese Communist Party's International Department minister, who is responsible for dealing with foreign political parties. Such greetings have been a tradition between North Korean and Chinese leaders, who once saw their relationship as "close as lips and teeth".
China has repeatedly urged North Korea to return to the so-called six-party talks, which are aimed at getting Pyongyang to give up its nuclear weapons.
Choe told the Chinese this format did not work. In 2009, Pyongyang said it would never return to the talks, which also included South Korea, the United States, Japan and Russia.
North Korea would instead seek bilateral talks with the various parties first, said the source, without elaborating.
Abandoning its nuclear weapons program could not be a prerequisite for talks, Choe told his hosts.
That makes talks with Washington a non-starter since U.S. officials say North Korea must take meaningful steps on denuclearization before there can be dialogue.
Choe told his Chinese hosts that Kim had consolidated his power since the death of his father, Kim Jong-il, in December 2011, through the weapons tests and war threats that saw Pyongyang put its armed forces on alert this year.
There has been repeated speculation that the North's young leader had been challenged by some elements in the military, although these assessments have been impossible to verify given the closed nature of North Korea.
"Through mobilizing troops, Kim Jong-un wanted to see who obeyed and who refused to obey his command," the source said.
Just under a year ago, Kim ousted Vice Marshal Ri Yong-ho, North Korea's leading military figure, as army chief of staff. A couple of days later North Korean media named Kim as marshal of the army.
"Many (officers) have been rounded up or sacked. Ri Yong-ho was arrested on counter-revolutionary crimes," the source said. He declined to say if Ri was jailed or executed.
"There had been some opposition to Kim Jong-un when he was named marshal. He has gotten rid of this."
Additional reporting by Matt Spetalnick in Washington. Writing by Dean Yates. Editing by David Chance and Mark Bendeich