Continued from page 2

Former Republican presidential candidate Jon Huntsman Jr., who served as U.S. ambassador to China under Mr. Obama until last year and then ran against Mr. Romney during the GOP primaries, likely would be in the running.

Mr. Romney’s outspoken affinity for Israel, along with his hard-line rhetorical posture toward Iran, could bring into the race even retiring Sen. Joe Lieberman, the Connecticut independent whom 2008 GOP nominee John McCain briefly considered as a running mate.