China, the biggest buyer of US Treasury securities, cut its holding in December to a 10-month low, the latest data from the Treasury Department showed on Tuesday.
China reduced its holding by $18.4 billion to $1.2461 trillion in December, coinciding with the country's sharpest monthly fall in foreign reserves.
The country's forex reserves dropped to $3.33 trillion in December, the lowest levels since 2012, according to official data.
Japan, the second largest foreign holder of U.S. Treasury securities, also cut its holding in December by $22.4 billion to $1.1225 trillion.
Net selling by foreign governments of U.S. securities, including Treasuries, agency debt, corporate bonds and stocks, totaled $51.3 billion, marking the biggest monthly outflow on record for official holders, reported Bloomberg citing the department.
Xinhua contributed to this story.