Treasury Secretary Janet Yellen has been reaching out to CEOs and business leaders to explain the "catastrophic" impact a US default on its debt would have on the US and global economies. Yellen is warning about the dangerous consequences of the current brinkmanship surrounding the debt ceiling and has been having one-on-one conversations to increase pressure on Republicans to raise the debt ceiling without conditions. President Joe Biden insists that Congress has a constitutional duty to raise the debt ceiling, which reflects previously spent federal money, without the conditions proposed by Republicans. Yellen told lawmakers last week that she expects Treasury to be unable to pay all government bills as early as June 1 without an increase in the federal debt limit. A default on US Treasury bonds comes with the risk of triggering a financial crisis, particularly since much global finance depends on the liquidity and security of US Treasury bonds. The growing concern around this issue is prompting both the White House and Congress to reach a resolution before the deadline arrives.