WASHINGTON (AP) — The Republican presidential nomination all but in hand, Mitt Romney is refocusing his efforts on challenging President Barack Obama, raising cash for the battle ahead and reconciling with onetime primary rival Rick Santorum.

Romney told supporters Tuesday in Manchester, N.H., that, in his words, "Tonight is the start of a new campaign."

The former Massachusetts governor is celebrating a sweep of five East Coast primaries — and blasting Obama as a man whose time in office has been marked by what Romney calls "false promises and weak leadership" in a time of economic struggle.

The contests were the first since Santorum conceded the race. The former Pennsylvania senator says he intends to sit down with Romney's representatives on Wednesday and with Romney himself in the next week or two.