"We should try our very best to avoid open armed conflict with China," Milley said in an interview with an American news network.
The military official added that the US already participated in two "great power wars," specifying that he was talking about World War I and World War II.
Speaking about China's possible "invasion" of Taiwan, Milley said that "it is entirely possible" for the US to repel the attack, adding that Washington wants a "peaceful outcome" between Beijing and Taipei.
Taiwan has been governed independently from mainland China since 1949. Beijing regards the island as its province, while Taiwan maintains that it is an autonomous entity but stops short of declaring independence. Beijing opposes any official foreign contacts with Taipei and regards Chinese sovereignty over the island as indisputable.