Ed Miliband told ITV News that if he becomes prime minister he will make sure his brother David is involved in British public life.
"I will make sure that he serves the country in one way or another because I think he's a huge talent," he told deputy political editor Chris Ship.
He said the brothers had "got past" the pain caused by the pair standing against each other for Labour leadership.
And he added that although he'd miss his brother in New York, he was "only a phone call away" and would "continue to be a support" across the pond.
David Miliband was nearly Prime Minister, and nearly Labour party leader, but his brother's rise has led him to take a back seat.
David Miliband will resign as an MP to take up a job in America, a move which is set to be announced today.