WASHINGTON -- Two commercial aircraft, one Russian and the other American, were one minute away from a mid-air, head-on collision near Puerto Rico, but maneuvered in time to avert catastrophe, a US official said Friday.

A Delta Boeing B737-800 and a Transaero Boeing B747-400, registered in Russia, were travelling toward one another on Thursday at the exact same altitude of 10,058 meters (33,000 feet), Peter Knudson of the National Transportation Safety Board (NTSB) said.

The two aircraft "came within zero feet vertical and one minute lateral separation at an altitude of 33,000 feet," Knudson said.

"The Transaero 747 descended 200-300 feet (60 to 90 meters) after receiving an alert from its Traffic Collision Avoidance System," he said.

He did not say how many passengers were aboard the two airplanes.

The near miss occurred at approximately 6:37 p.m. (2237 GMT) Thursday over the Atlantic Ocean, 288 kilometers (179 miles) north of San Juan, Puerto Rico.

Fifteen minutes of lateral separation between planes is required in that area, Knudson said.

Delta Flight 485 was en route from New York's Kennedy Airport to Port of Spain, Trinidad and Tobago.

The NTSB did not indicate the route of the Transaero jet but gave the flight number as 554.