United CEO Scott Kirby confirmed on Monday that he had approached American about a potential merger, but the offer was rejected by American."I proposed to American Airlines to explore the possibility of a merger because I thought together we could create some incredible value for our customers," Kirby said in a statement. He said he shared a "big and bold vision" and was confident it would win regulatory approval.

American has rejected the idea, with its CEO Robert Isom saying last week that such a merger would be bad for customers and "anticompetitive."

Kirby proposed the idea to the Trump administration earlier this year, hoping the merger would create a major global airline that could rival foreign rivals, according to a person familiar with the matter.

"I had hoped to present this idea to American Airlines, but they refused to engage and responded by publicly closing the door. Without a willing partner, something of this magnitude simply cannot move forward," Kirby said in a statement Monday.