Democratic President Joe Biden called on Congress and banking regulators to strengthen the rules for banks "to make it less likely this kind of bank failure will happen again," while officials said customers at SVB and New York-based Signature Bank (SBNY.O), which also collapsed, would have access to all their deposits starting Monday, and announced a new facility to give banks access to emergency funds.

An administration official said there was no timeline for Biden to make any particular requests of Congress as his aides were still working to manage the immediate situation and better understand what caused the crisis and what to ask of lawmakers.

At issue are changes to the Dodd-Frank Act passed in 2018, pushed by Republicans, which raised the threshold at which banks are considered systemically risky and subject to stricter oversight to $250 billion from $50 billion. Silicon Valley Bank had $209 billion in assets at the end of last year, while Signature Bank had some $110 billion.

"Let's be clear. The failure of Silicon Valley Bank is a direct result of an absurd 2018 bank deregulation bill signed by (Republican former President) Donald Trump that I strongly opposed," Senator Bernie Sanders said in a statement.

Republicans rejected the idea that the changes made during Trump's four years in the White House were to blame.

"That is absolutely not the case," said Bill Hagerty, Senate Appropriations Subcommittee on Financial Services and General Government Ranking Member.

"What we've had, I think, in every sense is a management failure both from the standpoint of SVB's management as well as the San Francisco Fed," said Hagerty in an interview following a briefing by Treasury Department and Federal Deposit Insurance Corp officials to a bipartisan group of lawmakers on Monday.

Hagerty said Congress should determine who was accountable among regulators at the San Francisco Federal Reserve Bank and within SVB's management before considering new regulations.

"Where was the San Francisco Fed?" he added, saying awareness of the bank's recent growth and business model should have led Fed officials to anticipate trouble.

Hagerty also said that he and Federal Reserve Chairman Jerome Powell spoke on Sunday and agreed that markets might remain choppy for a few days. "My hope and expectation is that as the markets digest the information that's there, the markets will calm and settle," the Tennessee Republican said.

Experts say SVB ultimately collapsed because it failed to manage its portfolio amid rapidly rising interest rates, and had a huge amount of uninsured deposits that were quick to leave when the stress was apparent.

In an op-ed for the New York Times, Democratic Senator Elizabeth Warren placed some of the blame at the feet of bank regulators, whom she accused of "letting financial institutions load up on risk."

"It's clear there were big misses here," said Jonah Crane, a partner with Klaros Group and former Treasury Department official. "For one, the Fed has only once ever stress tested for a high interest rate environment, despite knowing they would have to raise rates."

Prospects for new banking legislation in a divided Congress are dim. As a result, regulators will also be in the spotlight for speedier tweaks, said Ian Katz, managing director of Capital Alpha Partners, in a note.

"There won't be legislation getting through Congress, and so regulators will be making the big decisions," he said.