North Korea has begun fueling a long-range rocket for an impending launch, a news report said Thursday, as President Barack Obama warned the liftoff would be a "provocative act" that would generate a UN Security Council response. North Korea says it will send a communications satellite into orbit on a multistage rocket sometime from Saturday to Wednesday. The US, South Korea and Japan think the reclusive country is using the launch to test long-range missile technology, and they've warned the move would violate a Security Council resolution banning it from ballistic activity. Regional powers have also begun to deploy ships to monitor the launch, and Japan is preparing to intercept any debris that might fall if the launch goes awry. These moves have prompted several threats of retaliation from Pyongyang. CNN television reported on its Web site that Pyongyang has begun the fueling the rocket. The report, citing an unidentified senior US military official, said the move indicates final preparations for the launch. Experts say the missile can be fired about three to four days after fueling begins. South Korea's Defense Ministry said it was aware of the report but declined to comment.