What did japan do in its effort to create a pacific empire

They did By taking over US, British, and French territories. 

Japan's expansion began in 1931. In the year, Japanese troops took over Manchuria in northeastern China. Six years later, Japanese armies swept into the heartland of China. They expected quick victory. Chinese resistance, however, caused the war to drag on. This caused a strain on Japan's economy. To increase their resources, Japanese leaders looked toward the rich European colonies of Southeast Asia.