As an American Navy aircraft carrier group heads toward Korea, China said Thursday that military force alone cannot end tensions on the Korean Peninsula. At the same time, an influential Chinese newspaper urged North Korea to stop its nuclear program in exchange for Chinese protection. Experts are worried that the North could soon conduct its sixth nuclear test or launch more missiles in defiance of United Nations resolutions and sanctions. The United States has also strongly warned that it will no longer be patient with the North. China is the North’s only major ally. It also gives a lot of aid to the country. But it wants the North to end its nuclear weapons program. China has called for negotiations to ease tensions. It also wants nuclear weapons removed from the peninsula.