U.S. Treasury Secretary Steven Mnuchin said Sunday that he held individual calls with CEOs of the nation's six largest banks, all of whom said their institutions had ample liquidity for lending to consumers, businesses and all other market operations despite the recent market turmoil.

The unusual statement, issued via the Treasury Department's verified Twitter feed, also noted that Mnuchin would chair a meeting of the President's Working Group on Financial Markets, which includes the Board of Governors of the Federal Reserve system, the Securities and Exchange Commission and the Commodities and Futures Trading Commission. 

"We continue to see strong economic growth in the U.S. economy, with robust activity from consumers and business," Mnuchin said in a statement. "With the government shutdown, Treasury will have critical employees to maintain its core operations at Fiscal Services, IRS and other critical functions within the department."

Munchin said he spoke with Brian Moynihan of Bank of America (BAC) , Michael Corbat of Citigroup (C) , David Solomon of Goldman Sachs (GS) , JPMorgan's (JPM) Jamie Dimon, James Gorman of Morgan Stanley (MS) and Tim Sloan of Wells Fargo (WFC) . From those conversations, the Treasury said, the CEOs "have not experienced any clearance or margin issues and that the markets continue to function properly." 

Today I convened individual calls with the CEOs of the nation's six largest banks. See attached statement. pic.twitter.com/YzuSamMyeT

— Steven Mnuchin (@stevenmnuchin1) December 23, 2018

The Sunday statement followed Tweets from Mnuchin on Saturday that appeared to quote President Donald Trump and were aimed at quashing speculation that the President was preparing to fire Federal Reserve Chairman Jerome Powell.  

"I totally disagree with Fed policy. I think the increasing of interest rates and the shrinking of the Fed portfolio is an absolute terrible thing to do at this time," Mnuchin quoted a conversation with the President. "Especially in light of my major trade negotiations which are ongoing, but I never suggested firing Chairman Jay Powell, nor do I believe I have the right to do so."

Early indications from U.S. equity futures suggest Wall Street will find its feet at the opening bell Monday, at least for the three and a half hours of trading scheduled, with contracts tied to the Dow Jones Industrial Average indicating a 62 point gain for the 30-stock average while those linked to the S&P 500 suggesting a 9-point advance for the broader benchmark.

The statements followed one of the worst weeks on Wall Street in at least a decade, with the S&P 500 extending its fourth quarter decline to to the lowest levels since July of 2017 and amid its the biggest December decline -- 12.45% -- since 1931 with selling accelerating after the Fed opted to raise rates for the fourth time this year last week despite vocal criticism from the President.

The broadest U.S. benchmark has fallen some 17.5% form its September 20 peak, while the tech-focused Nasdaq has given back more than 22% since hitting a record high on August 29, officially pulling the index into bear market territory.

Here are all the years in $SPX history (since inception in 1923) where the index set its lowest point of the year in December and the date it was set.

2018 data is through Dec 21 and will change if we set a new low before New Year's Eve.

I can't believe I had to explain that. pic.twitter.com/IE52FSOf9G

— OddStats (@OddStats) December 23, 2018

Markets were also spooked by Friday comments from White House Trade Advisor Peter Navarro, who told the Japanese business daily Nikkei that it would be "difficult" to reach a trade deal with China before the expiration of a 90-day window agreed earlier this month between Presidents Trump and Xi Jinping.