In appearances on the political talk show circuit Sunday, Lew warned that "Congress needs to do its job" and reopen the government and raise the ceiling limit or the United States will default on its financial obligations for the first time.
The problem isn't U.S. President Barack Obama's "willingness to negotiate," but Republicans who won't vote for a clean funding bill without strings attached, like the demand to alter or delay the Affordable Care Act, Lew said in an appearance on CBS' "Meet the Press."
Boehner said he doesn't have the majority votes necessary to pass such a bill.
"Well then why doesn't he put it on the floor and give it a chance?" Lew asked. "There's a majority in Congress that I believe is prepared to do the right thing, to open the government and make sure we don't cross over that abyss."
"We're on the verge of going into a place we've never been," he said. "If we run out of cash to pay our bills, there is no option that permits us to pay all of our bills on time -- which means that a failure of Congress to act would for the first time put us in a place where we're defaulting on our obligations as a government because of Congress's failure to act," Lew warned on NBC's "Meet the Press.
If the debt ceiling isn't raised by Oct. 17, the Treasury will only have $30 billion on hand to pay its bills.
In an appearance on CNN's "State of the Union," Lew said that while that sounds like a lot of money, it's only a fraction of what the United States spends on a daily basis.
"When you think about the cash flow of the government of the United States, we have individual days when our negative or positive cash flow is $50 or $60 billion," he said. "So, $30 billion is not a responsible amount of cash to run the government on."
He warned that should Congress not raise the debt ceiling, the United States may default on its debts, putting Social Security, disability and veterans payments at risk.
"If they don't extend the debt limit, we have a very, very short window of time before those scenarios start to be played out," he said.
In an appearance on "Fox News Sunday," Lew said President Barack Obama would be willing to negotiate future budget needs with Congress, if Congress ends the government shutdown.
"Congress has to do its job," he said. "We've just spent the last several months with Congress creating this ridiculous choice where either you repeal the Affordable Care Act or you shut down the government or default on the United States. That is not the way we should do business. ... They need to open the government. They need to fund our ability to pay our bills."