Updated

The Federal Aviation Administration is undertaking a comprehensive review of the critical systems of Boeing's 787s, the aircraft maker's newest and most technologically advanced plane, after a fire and a fuel leak earlier this week, the agency said in a press conference Friday.

The review will have special focus on the electrical system, and will also include the design, manufacture and assembly of those systems, FAA chief Michael Huerta said.

"The number one priority at the Department of Transportation is protecting the safety of the traveling public," Secretary of Transportation Ray LaHood said.

The 787, which Boeing calls the "Dreamliner," relies more than any other modern airliner on electrical signals to help power nearly everything the plane does.

It's also the first Boeing plane to use rechargeable lithium ion batteries, which charge faster and can be molded to space-saving shapes compared to other airplane batteries. The plane is made with lightweight composite materials instead of aluminum.

A Boeing official said the company is working with the FAA. The FAA statement gave no indication that the agency intends to limit or prohibit the 787 from flying during the review.

Boeing executive Ray Conner said the company has “complete confidence” in the 787.

"We are absolutely confident in the reliability and performance of the 787," Boeing spokesman Marc Birtel said.

"We are working with the FAA and our customers to ensure we thoroughly understand any introductory issues that arise. While we take each issue seriously, nothing we've seen in service causes us to doubt the capabilities of the airplane,” Birtel said.

Huerta said the FAA spent 200,000 hours in the certification process of the 787. "We are confident about the safety of this aircraft," Heurta said.

"We will conduct the review until we are satisfied."

A fire ignited Monday in the battery pack of an auxiliary power unit of a Japan Airlines 787 empty of passengers as the plane sat on the tarmac at Boston's Logan International Airport.

It took firefighters 40 minutes to put out the blaze. Also this week, a fuel leak delayed a flight from Boston to Tokyo of another Japan Airlines 787.

On Friday, Japan's All Nippon Airways reported two new cases of problems with the aircraft. ANA spokeswoman Ayumi Kunimatsu said a very small amount of oil was discovered leaking from the left engine of a 787 flight from southern Japan's Miyazaki airport to Tokyo.

The jet returned to Miyazaki, but after checks found no safety risk it flew to Tokyo. ANA said on another flight, to Matsuyama on the island of Shikoku, glass in a cockpit window cracked and the aircraft was grounded for repairs.

Boeing has insisted that the 787's problems are no worse than what it experienced when its 777 was new in the mid-1990s. That plane is now one of its top-sellers and is well-liked by airlines.

The Associated Press contributed to this report.