U.S. President Donald Trump said Thursday he is "very angry" at North Korea's ballistic missile test earlier this month, and that boosting a missile defense system for Japan and South Korea is among the options to counter provocative acts by Pyongyang.

In an interview with Reuters, Trump said he wants to build up the U.S. nuclear arsenal to ensure it is at the "top of the pack," reversing his predecessor Barack Obama's goal of achieving a world without nuclear weapons.

Trump said China could solve North Korea's nuclear issue "very easily if they want to," urging Beijing to exert more influence on Pyongyang to get it to rein in its missile and nuclear weapons programs, which violate U.N. Security Council resolutions.