President George W Bush has urged the "urgent" passing of a bill that would retroactively shield telecoms firms which helped the government eavesdrop.
He called on the House of Representatives to approve the law, already passed by the Senate.
An initial act, allowing warrantless tapping of phone calls and e-mails of suspected terrorists, expired on 17 February but did not grant immunity.
Lawsuits have been filed against some of the firms which took part.
They are accused of violation of privacy.
He told the White House on Tuesday "abusive" lawsuits against telecoms firms would "aid our enemies" by teaching them how to duck surveillance.
'Dangerous intelligence gap'
The House of Representatives allowed the law to expire this month after refusing to rubber stamp a Senate bill that would give telecommunication firms immunity from lawsuits.
The legislation allowed government spying on foreign telephone calls and electronic correspondence without court permission.
"The law expired, the threat to America has not expired," Mr Bush said.
Mr Bush told the White House on Tuesday "a dangerous intelligence gap" had opened up last year before the temporary Protect America Act was passed in August.
"Allowing these lawsuits to proceed would be unfair," he said. "If any of these companies helped us, they did so after being told by our government that their assistance was legal and vital to our national security.
"Allowing the lawsuits to proceed could aid our enemies, because the litigation process could lead to the disclosure of information of how we conduct surveillance and it would give al-Qaeda and others a roadmap as to how to avoid the surveillance."
He warned firms would refuse to co-operate with the intelligence services if they were not granted immunity from lawsuits.
In a wide-ranging speech Mr Bush also:
- called on Turkey to "move quickly" and "get out" of Iraq, following its military incursion - now in its sixth day - over the border to flush out Kurdish rebel bases
- said his political opponents kept making the "same old call for withdrawal" of US troops from Iraq, refusing to acknowledge any security gains over the last year
- said the forthcoming Beijing Olympics would not stop him expressing "deep concerns" about issues such as religious freedom with the Chinese leadership
- insisted the US was not heading for a recession and rejected, for now, calls for any extra economic stimulus efforts.