Mitt Romney vowed to take the White House from President Obama after victories in five primaries, effectively ending the Republican nomination process.
Addressing supporters in New Hampshire, he announced the start of a new campaign and attacked Mr Obama as a president who had shown only “false promises and weak leadership” during economic hardship.
“To all the thousands of good and decent Americans I’ve met who want nothing more than a better chance, a fighting chance, to all of you I have a simple message: Hold on a little longer,” he said.
The former private equity boss, 65, pledged to “stop the unfairness of one generation passing larger and larger debts on to the next”. He will now launch fundraising efforts to boost his $10 million war chest ready for what is expected to be the most expensive presidential election ever. Mr Obama is said to have already raised $104 million.
Mr Romney’s overwhelming victories in Connecticut, Rhode island, Delaware, Pennsylvania and New York were the first since main rival, Rick Santorum, conceded.
