FBI Director William Sessions, anticipating a long investigation into the crash of Pan Am Flight 103 in Scotland, said Sunday he welcomes any information PLO Chairman Yasser Arafat can provide.

Arafat "has a great deal of information, a wealth of information he can give us," Sessions said. The FBI director added that contacts between the FBI and the leader of the Palestinian Liberation Organization presumably could be set up by the State Department.U.S. and PLO officials recently opened talks after Arafat disavowed terrorism and recognized Israel's right to exist.

Sessions, interviewed on ABC's "This Week with David Brinkley" and on NBC's "Meet the Press," said it may take a long time to discover who is responsible for the jetliner crash.

"We're set up for the long haul," he said. Sessions also said that 62 bodies from the crash that killed 270 people have been identified through fingerprinting.

Sessions said, "I'm very optimistic. We have a pattern and reputation for being able to solve" such crimes.

While welcoming Arafat's help in identifying possible suspects in the Pan Am crash, Sessions said he opposes any attempt by the PLO leader to retaliate by killing any suspects.

Asked about reports that Arafat is considering organizing an assassination team, Sessions said, "We believe in the system of justice. We hope those people are handled in the courts."

Arafat has blamed terrorists for bringing down the jetliner, condemning it as an "inhuman criminal action."

Sessions said he has no evidence to confirm the bomb was the work of terrorists, rather than an individual acting against someone on board the jet.

Federal Aviation Administrator Alan McArtor, also appearing on "Meet the Press," defended the policy of not publicizing threats to airliners.

"These threats are transmitted on a routine basis," he said.

But McArtor conceded that it was a mistake for the United States to warn overseas embassy personnel about the threat to Pan Am jets while not alerting the public.

"Personally, I don't think it was managed well," he said.

McArtor said an alert has been issued to the Athens airport and others in the Mediterranean area to be on the lookout for false passports.

"There has been movement of some known terrorists who have in their possession false transports," McArtor said.

He also said the FAA will negotiate with European allies to seek improved airline security.

"This is a threat against civil aviation. It's not just isolated to American carriers," he said.

On CBS' "Face the Nation," Sen. William Cohen, R-Maine, and Rep. Lee Hamilton, D-Ind., said the United States should keep open the possibility of military retaliation against any nation linked to terrorist attacks.