It's still likely that the US could default on its obligations in early June if Congress doesn't act, Treasury Secretary Janet Yellen said Monday.

The looming deadline is keeping the pressure high on House Republicans and the White House to bridge their differences and address the debt ceiling in the coming days. President Joe Biden is expected to meet again on Tuesday with House Speaker Kevin McCarthy and other top congressional leaders.

"With additional information now available, I am writing to note that we still estimate that Treasury will likely no longer be able to satisfy all of the government's obligations if Congress has not acted to raise or suspend the debt limit by early June, and potentially as early as June 1," Yellen wrote to McCarthy.

This story is breaking and will be updated.