American is the first U.S. airline to report an impact from the attack on Colonial, which carries nearly half the fuel consumed along the U.S. East Coast.

"We are closely monitoring the situation and working around the clock to ensure that we have an adequate supply of fuel across our network," American, the largest U.S. airline said, adding that the two impacted flights are expected to return to the original schedule on May 15. 

American said its daily flight from Charlotte to Honolulu will now stop in Dallas, where passengers will change planes before flying onto Honolulu, while its daily flight from Charlotte to London will stop in Boston for additional fuel.

(Reporting by Tracy Rucinski; Editing by Christian Schmollinger and Leslie Adler)