Bush and senior officials in his administration have said they did not think changes were needed to empower the National Security Agency to eavesdrop without court approval on communications between people in the U.S. and overseas when terrorism is suspected.

But Sen. Arlen Specter, R-Pa., and other critics contend the program skirted a 1978 law that required the government to get approval from a secretive federal court before Americans could be monitored.

"We're getting close with the discussions with the White House, I think, to having the wiretapping issue submitted to the Foreign Intelligence Surveillance Court," Specter told "Fox News Sunday."

Although Specter did not mention any specific legislation in his remarks Sunday, the context of discussions between members of Congress and administration officials has revolved around some tweaking of the law that would acknowledge the legality of the surveillance program while at the same time placing it under additional oversight.

Specter has a drafted bill that would require the attorney general to get approval from the FISA court every 45 days to preserve the surveillance program.

Other Republican lawmakers have been working on alternative legislation aimed at writing the administration's program into law.

While insisting the program is legal now, White House officials have been saying for several months that they are willing to work with Congress if it feels further "codification" of the program is needed.

The administration has asserted that a post-Sept. 11, 2001, congressional resolution approving the use of military force covered the surveillance of some domestic communications.

Specter has said that the president "does not have a blank check" and he has sought to have administration ask the special court to review the program.

After the program was disclosed by The New York Times in December, the White House opposed changing the law. Over time, that position has shifted gradually.

When the president's nominee to head the CIA had confirmation hearings in the Senate in May, Michael Hayden told Sen. Richard Durbin, D-Ill., that he would support a congressional debate on modifying the law.

"We're having a lot of conversations about that," Specter said Sunday. He added that he and Vice President Dick Cheney have exchanged letters and that Cheney has indicated that he was serious about discussing the issue.

"I've talked to ranking officials in the White House, and we're close," Specter said. "I'm not making any predictions until we have it all nailed down, but I think there is an inclination to have it submitted to the Foreign Intelligence Surveillance Court, and that would be a big step forward for the protection of constitutional rights and civil liberties."