No changes to US military presence in Aust AMERICA'S military presence in Australia will not change following threats of nuclear attacks by North Korea, US ambassador Jeffrey Bleich says. However, the US is taking the threats seriously in all of its missions around the world. "We're not aware of any capability by North Korea, even with weapons they've identified ... being able to conduct a strike in Australia," he told AAP in Canberra. From that perspective, no we haven't changed our posture here. Mr Bleich said the US had been very clear to China about its views on North Korea, given the special relationship between the Asian nations. "It's incumbent on (China) to express the concerns of all of us about the belligerence of North Korea," he said. Prime Minister Julia Gillard is on her way to China where she is expected to discuss tensions on the Korean peninsula with regime leaders. The US has moved to protect military bases on Guam, an island about 3380km southeast of North Korea and home to 6000 American military personnel, submarines and bombers. Mr Bleich noted North Korea had a relatively new leader. "Where there are capacity for miscalculations, missteps or reckless behaviour ... we don't take anything for granted," he said.