House Republicans took another step toward a major increase in defense spending, as a key panel approved a spending package to increase Pentagon funding by $60 billion.

"Congress's number one responsibility is to provide for the defense of this nation," Rep. Kay Granger, R-Texas, who leads the House Appropriations defense subcommittee, said Thursday. "It is this bill that fulfills that most fundamental constitutional duty."

The defense bill provides $658 billion in funding for the military next year, a figure that exceeds President Trump's request by $28 billion. That extra funding will be devoted to a "defense readiness fund" that gives Defense Secretary Jim Mattis broad power to use to finance military programs that lost funding due to recent budget fights.

Democrats agreed on the need for such patches, but warned the legislation sets the stage for another major spending fight this fall.

"I agree with [Granger] that the legislation as written has the potential to fill many of the military's readiness gaps," Indiana Rep. Pete Visclosky, Granger's Democratic counterpart on the panel, said Thursday. "Unfortunately, at this moment, I am not optimistic of this bill's independent enactment by midnight on September 30th."

Visclosky and other Democrats noted a 2011 debt ceiling and spending deal imposed caps on federal defense and non-defense spending. They agreed the defense spending should rise beyond those caps, but worried Republicans might try to push such an increase to Trump's desk without providing a similar increase in non-defense spending.

"This type of piecemeal approach is unacceptable, and, yes, it's irresponsible," said Rep. Barbara Lee, D-Calif.

But Granger, a Texas Republican, emphasized military leaders are worried the United States will lose "our ability to project power" due to underfunding of the military.

"Our military has made it very clear that we must provide predictable funding," Granger said.