COLOGNE/WASHINGTON (REUTERS) - Germanwings said it was unclear what caused its Airbus A320 aircraft to crash in the French Alps on Tuesday but that there had been no problems with the plane before takeoff.

In Washington, DC, the White House said the crash does not appear to have been caused by a terror attack, the White House said, according to a report by Fox News.

The Lufthansa unit's Managing Director Thomas Winkelmann told journalists at a news conference yesterday, hours after the crash: "There were no anomalies on the plane."

He said Airbus delivered the plane to Lufthansa in 1991, after which it flew exclusively for the German flagship carrier until it was transferred to Germanwings' fleet last year. That makes the aircraft older than the 11.5-year average age of Lufthansa's fleet of 615 planes.

"That is acceptable because maintenance standards inside the Lufthansa group are known as very high worldwide," Winkelmann said. "As long as you have your maintenance schedule in place and follow all the procedures together with the manufacturer, there is absolutely no issue with the age of an airplane."

Routine maintenance was last performed on the crashed A320 by Lufthansa Technik on Monday, and the last regular major round of maintenance was in summer 2013, he said.

The pilot at the Airbus's helm has been flying Lufthansa and Germanwings for more than 10 years, he added.

"We need to use all of the Lufthansa group's resources, maintenance, flight operations, cockpit crews and all other experts, to jointly with authorities and with Airbus find out as quickly as possible what happened," Winkelmann said.

In the United States, Fox News network quoted White House National Security Council spokeswoman Bernadette Meehan as saying: "There is no indication of a nexus to terrorism at this time."