The chief executive of the Toyota Motor Corporation said Monday that he is pushing his company’s engineers to develop a plug-in hybrid-electric vehicle with a lithium-ion battery before 2010, raising the stakes in a race with General Motors.

The comments by Katsuaki Watanabe came at a briefing here on the sidelines of the Detroit auto show, which opened to the press on Sunday.

Mr. Watanabe said he welcomed a competition with G.M., which plans to introduce its own lithium-ion hybrid, the Chevrolet Volt, around 2010.

He said the contest would help reduce the “negative aspects” of automobiles, and ultimately help the environment.