NEW YORK: US money market fund assets jumped to their highest level since 2009 as investors unnerved by the rapid deterioration in trade talks between China and the United States piled into these cash-like investments, a private report showed on Wednesday.

Fears about the clash between world's two biggest economies grew after US President Donald Trump pledged last Thursday to impose a 10% tariff on $300 billion worth of Chinese-made goods.

Beijing responded by letting its currency weaken to its lowest level against the greenback in a decade on Monday. State media said local firms suspended buying US agricultural products.

Then, the Treasury Department late on Monday labeled China a currency manipulator.

These developments touched off a dramatic sell-off in stocks and risky assets around the world and a safe-haven stampede into cash, yen, gold and some government bonds.

Total money fund assets grew by $57.54 billion to $3.301 trillion in the week ended Aug. 6, marking their highest level since November 2009, the Money Fund Report said on Wednesday.

The asset increase in the money fund industry was the biggest one so far this year,

Taxable money market fund assets increased by $57.21 billion to $3.165 trillion, while tax-free assets edged up by $330.70 million to $136.42 billion, according to the report, published by iMoneyNet.

The iMoneyNet average seven-day simple yield for taxable money funds fell to 1.86%, the lowest level since November, from 1.94% a week ago. The weighted average maturity among taxable funds shortened by one day to 29 days.

The iMoneyNet average seven-day yield for tax-free and municipal funds was unchanged at 1.01%. The weighted average maturity of tax-free funds was unchanged at 28 days.

US interest rates have fallen broadly after the Federal Reserve a week ago lowered borrowing costs for the first time since 2008 due to trade tensions and sluggish inflation.