Foreign demand for long-term US financial assets fell in April as both China and Japan trimmed their holdings of Treasury securities.

The Treasury Department said Monday that net purchases of stocks, notes and bonds obtained by foreigners fell to $US11.2 billion ($13.85 billion) in April, from $US55.4 billion ($68.51 billion) in March.

China, the largest holder of US Treasury securities, trimmed its holdings to $US763.5 billion ($944.22 billion) in April, from $US767.9 billion ($949.67 billion) in March. Japan, the second largest holder of Treasury securities, reduced its holdings to $US685.9 billion ($848.26 billion), from $US686.7 billion ($849.25 billion) a month earlier.

Treasury Secretary Timothy Geithner travelled to Beijing earlier this month to assure the Chinese government that the Obama administration is determined to get control of an exploding US budget deficit, which is projected to hit a record $US1.84 trillion ($2.28 trillion) this year.

China's holdings of Treasury securities represent about 10 per cent of America's publicly held debt.