Foreign countries dumped US government securities after the war in Iran broke out in March

The soaring energy prices prompted countries to sell some of their dollar-based assets to finance their own currency interventions, CNBC reports.

China reduced its holdings to $652.3 billion in March. That's about six percent less than in February and the lowest level since September 2008.

Japan, the single largest holder of US government debt, reduced its holdings by approximately $47 billion, to just over $1,191 billion.

"Given the increased financial uncertainty since the Gulf War began, and the resulting pressure on exchange rates, especially in Asia, this is not surprising," says Frederic Neumann, chief economist for Asia at HSBC.

Corrected: An earlier version stated the wrong figure regarding Japan's holdings.