Chinese President Xi Jinping will push President Barack Obama next week to resume talks on the North Korean nuclear issue, a senior diplomat said on Thursday, a meeting that could also touch on hacking and the South China Sea.

China is North Korea's sole major ally but it strongly disapproves of its nuclear program and was angered by its fourth nuclear test in January and a subsequent rocket launch.

While China has signed up for tough new U.N. sanctions against North Korea, it has said repeatedly sanctions are not the answer and that only a resumption of talks can resolve the dispute over North Korea's weapons program.

Chinese Vice Foreign Minister Li Baodong said Xi and Obama will have their first meeting this year on the sidelines of a nuclear security summit in Washington next week, and will talk about North Korea.

"On this issue, China's position is consistent. We are dedicated to the decentralization of the Korean peninsula," he told a news briefing.

"We think this issue should be resolved via dialogue and consultation. We are dedicated to maintaining peace and stability on the peninsula. On this important issue, Presidents Xi and Obama will have an opportunity to have a full exchange of views."

China has been calling for a resumption of so-called six-party talks between the two Koreas, China, the United States, Japan and Russia aimed at curbing North Korea's nuclear ambitions. Russia has also urged Pyongyang to return to negotiations.

Numerous efforts to restart the talks have failed since they collapsed following the last round in 2008.

North Korean leader Kim Jong Un said last week the country would soon test a nuclear warhead and ballistic missiles capable of carrying nuclear warheads in what would be a direct violation of U.N. resolutions.

The North's state media said on Thursday the country had successfully tested a solid-fuel engine that boosted the power of its rockets, indicating it is continuing to develop an intercontinental ballistic missile, also in defiance of the sanctions.

China has also been upset by some U.S. moves, including new unilateral U.S. sanctions against Pyongyang and the possible deployment of a missile defense system to South Korea that Beijing says could harm its security.

North Korea is not the only issue Beijing and Washington do not see eye to eye on.

Hacking has been a sore spot. In September, Obama said he and Xi had agreed that neither government would knowingly support cyber theft of corporate secrets to support domestic businesses

Li said disagreements on the hacking issue had been "hyped up" by the media, but that the two countries had a dialogue mechanism which was working well.

On the South China Sea, where China's increasingly assertive territorial claims have alarmed its neighbors and the United States, Li said China "has its own point of view and position".

"Of course if this issue comes out, President Xi will explain this position to the U.S. side," he added.

China claims most of the energy-rich waters through which about $5 trillion in ship-borne trade passes every year. Neighbors Brunei, Malaysia, the Philippines, Taiwan and Vietnam also have claims.