Japan surpassed China to become the largest foreign holder of U.S. Treasuries in June, with its holdings at the highest level in nearly three years, U.S. Treasury Department said Thursday.

Japan's holdings of U.S. Treasuries increased by 21.9 billion U.S. dollars in June to reach 1.1229 trillion dollars, according to data from the department. It has been more than two years since Japan held more U.S. Treasuries than China.

China, meanwhile, held 1.1125 trillion U.S. dollars of U.S. Treasuries in June, a slight increase of 2.3 billion U.S. dollars from the previous month, after dropping for three months in a row.

Combined, China and Japan still held more than one-third of the total foreign holdings of U.S. Treasuries in the month.

Overall, foreign holders of U.S. Treasuries had 6.6363 trillion U.S. dollars of government debt in June, up 97.2 billion U.S. dollars from May, indicating a growing demand for the safe-haven asset.