UPDATE 1-US lawmaker troubled by sag in support for defense

* Murtha notes war spending bill nearly failed

* Says Pakistan situation biggest single U.S. threat

* Considering measure to add F-22s to 2010 budget (Adds quotes from Murtha, byline)

By Andrea Shalal-Esa

WASHINGTON, June 24 (Reuters) - The powerful head of the House of Representatives subcommittee that controls the purse strings of the Pentagon, said on Wednesday he was troubled by ebbing support for defense from fellow lawmakers.

Representative John Murtha, chairman of the defense subcommittee of the House Appropriations Committee, told reporters there was no question that defense spending was going to decline in coming years, but the country faced new threats that needed to be addressed.

He cited a "sea change" in support for defense among U.S. lawmakers, saying the recent supplemental war spending bill for fiscal 2009 nearly failed, and would not have passed without strong intervention by House Speaker Nancy Pelosi.

"Defense is going to start to go down. There's no question about it. The public has lost interest," the Democrat from Pennsylvania said.

"You're going to see a change, a sea change. I'm surprised myself at how little interest there is in what's going on in Iraq and Afghanistan, and yet we've got troops deployed."