SAN FRANCISCO (CBS/AP) – Transportation officials said the new Transbay Transit Center in San Francisco will cost $300 million more than estimated, and warned that costs could grow higher.

Steve Heminger, executive director of the Metropolitan Transportation Commission, said that money earmarked for future projects will be used to pay for the increase.

READ MORE: San Leandro Community Rallies for Reform on Anniversary of Steven Taylor's Police Shooting Death

When completed, the now $1.9 billion first phase of the transportation hub near downtown San Francisco will first serve buses from seven transit agencies.

In the future, the site will be a stop for California’s high-speed rail system and regional electric trains.

READ MORE: Lodi Parachute Center Skydiver Dies After Chute Gets Tangled on Descent

The project’s first phase includes building and maintaining a temporary terminal while the new 5-story facility is being constructed.

Officials blamed part of the cost spike on increased federal security requirements.

(Copyright 2013 by CBS San Francisco. All Rights Reserved. This material may not be published, broadcast, rewritten, or redistributed.)

MORE NEWS: Saratoga Resident Displaced in 2-Alarm House Fire Sunday Morning