WASHINGTON - President Barack Obama said on Wednesday that the U.S. House of Representatives is working to approve a comprehensive overhaul of the U.S. healthcare system by the end of July.

Obama spoke after a White House meeting with House Speaker Nancy Pelosi and other influential Democrats who will take the lead on shaping the healthcare legislation.

We don't have any excuses. The stars are aligned, said Obama, who has devoted much of this week to his drive to spur momentum behind the healthcare legislation.

The legislation is expected to generate a partisan battle in Washington. Republicans say Obama's proposal to create a new public health plan to cover millions of uninsured Americans would undermine the private health care market and exacerbate already huge budget deficits.

The House is working to pass a comprehensive healthcare reform bill by July 31, before they head out for the August recess, and that's the kind of urgency and determination that we need to achieve what I believe will be historic legislation, Obama said.

Pelosi, speaking before Obama, vowed that healthcare legislation will be on the floor of the House by the end of July.