WASHINGTON (AFP) - The US military would be able to defend the United States against any ballistic missile fired by the North Korean regime, a US general said on Tuesday. "If we felt the North Koreans were going to shoot a ballistic missile at us today, I am comfortable that we would have an effective system that would meet that need," Air Force General Victor Renuart, head of US Northern Command and North American Aerospace Defence Command, told a congressional hearing. Answering questions about the reliability of land-based US anti-missile weaponry, Renuart told the Senate Armed Services Committee the military was focused on North Korea as "a very limited threat." "North Korea is the system that we're fixed on," he said. North Korea has said it plans to launch a communications satellite next month, scheduled for April 4-8. But the United States believes the real aim is to test a long-range ballistic missile that could, in theory, reach Alaska. North Korea has resisted pressure from the United States and its allies to call off the rocket launch and warned that any attempt to shoot it down would be regarded as an act of war. At the same time, the regime has also stepped up its rhetoric against South Korea, even sporadically closing off access to a key joint industrial complex. North Korea first tested its Taepodong-2 missile in 2006, but it failed after 40 seconds. Three months later it staged an underground nuclear weapons test. As North Korea pushed ahead with plans for a rocket launch, China voiced its concern Tuesday over what it said was an increasingly uncertain situation on the Korean peninsula. The reliability of the costly US missile defense system has been the subject of intense debate in the United States, with skeptics questioning whether the land-based part of the system has faced tests under realistic conditions. The US has missile defense weaponry on Navy Aegis ships in the Sea of Japan as well as interceptors based in California and Alaska. According to the US Missile Defense Agency, the land-based system has worked successfully in 37 of 47 tests against a range of missile types. President Barack Obama's administration has not issued any warning that it plans to shoot down a possible North Korean missile. In 1993, the North Korean regime sought to test another new US president, Bill Clinton, announcing it would withdraw from the Nuclear Non-Proliferation treaty.