Al Qaeda is stepping up its efforts to sneak terror operatives into the United States and has acquired most of the capabilities it needs to strike here, according to a new U.S. intelligence assessment, The Associated Press has learned.

The draft National Intelligence Estimate is expected to paint an increasingly worrisome portrait of Al Qaeda's ability to use its base along the Pakistan-Afghan border to launch and inspire attacks, even as Bush administration officials say the U.S. is safer nearly six years into the war on terror.

Among the key findings of the classified estimate, which is still in draft form and must be approved by all 16 U.S. spy agencies:

— Al Qaeda is probably still pursuing chemical, biological or nuclear weapons and would use them if its operatives developed sufficient capability.

— The terror group has been able to restore three of the four key tools it would need to launch an attack on U.S. soil: a safe haven in Pakistan's tribal areas, operational lieutenants and senior leaders. It could not immediately be learned what the missing fourth element is.

— The group will bolster its efforts to position operatives inside U.S. borders. In public statements, U.S. officials have expressed concern about the ease with which people can enter the United States through Europe because of a program that allows most Europeans to enter without visas.

The document also discusses increasing concern about individuals already inside the United States who are adopting an extremist brand of Islam.

National Intelligence Estimates are the most authoritative written judgments that reflect the consensus long-term thinking of senior intelligence analysts.

Government officials, who spoke on condition of anonymity because the report has not been finalized, described it as an expansive look at potential threats within the United States and said it required the cooperation of a number of national security agencies, including the CIA, FBI, Homeland Security Department and National Counterterrorism Center.

National security officials met at the White House on Thursday about the intelligence estimate and related counterterrorism issues. The tentative plan is to release a declassified version of the report and brief Congress on Tuesday, one government official said.

Ross Feinstein, spokesman for National Intelligence Director Mike McConnell, declined to discuss the document's specific contents. But he said it would be consistent with statements made by senior government officials at congressional hearings and elsewhere.

The estimate echoes the findings of another analysis prepared by the National Counterterrorism Center earlier this year and disclosed publicly on Wednesday. That report — titled "Al Qaeda better positioned to strike the West" — found the terrorist group is "considerably operationally stronger than a year ago" and has "regrouped to an extent not seen since 2001," a counterterrorism official familiar with the reports findings told The Associated Press.