WASHINGTON (AP) — U.S. Treasury Secretary Steven Mnuchin called the CEOs of six major banks Sunday in an apparent attempt to reassure jittery financial markets coming off a turbulent week in the stock market that is now bracing for potential repercussions from a partial shutdown of the U.S. government.

In an unusual move, Mnuchin disclosed the calls with the heads of Bank of America, Citi, Goldman Sachs, JP Morgan Chase, Morgan Stanley and Wells Fargo in a tweet about the private conversations.

Mnuchin said the CEOs all assured him they have ample money to finance all their normal operations, even though there haven't been any serious liquidity concerns rattling the market.

Worries about slowing economic growth and rising interest rates saddled the U.S. market with its worst week in more than seven years.