BEIJING/SEOUL - The United States and South Korea will go ahead with joint military drills next week, the top U.S. military official said on Thursday, resisting pressure from North Korea and its ally China to halt the contentious exercises.North Korea's rapid progress in developing nuclear weapons and missiles capable of reaching the US mainland has fueled a rise in tensions in recent months.Pyongyang threatened last week to fire missiles towards the US Pacific territory of Guam and US President Donald Trump warned soon after that North Korea would face "fire and fury" if it threatened the United States.Annual military drills involving tens of thousands of U.S. and South Korean troops are due to begin on Monday. China, North Korea's main ally and trading partner, has urged the United States and South Korea to scrap the drills in exchange for North Korea calling a halt to its weapons programs.Joseph Dunford, Chairman of the US Joint Chiefs of Staff, said the exercises were "not currently on the table as part of the negotiation at any level.""My advice to our leadership is that we not dial back our exercises. The exercises are very important to maintaining the ability of the alliance to defend itself," Dunford told reporters in Beijing after meeting his Chinese counterparts."As long as the threat in North Korea exists, we need to maintain a high state of readiness to respond to that threat," he said.Fan Changlong, a vice chairman of China's powerful Central Military Commission, told Dunford that China believes the only effective way to resolve the issue is through talks."China believes that dialog and consultations are the only effective avenue to resolve the peninsula issue, and that military means cannot become an option," China's Defense Ministry cited Fan as saying.North Korea, which denounces the drills as a preparation for war, has fired missiles and taken other steps in the past in response to the war games.The United States and South Korea remain technically still at war with North Korea after the 1950-53 Korean conflict ended with a truce, not a peace treaty.