WASHINGTON - US Republican presidential hopeful Mitt Romney on Tuesday night pivoted to the general election with a rousing speech exalting his vision for a better America, as he is expected to win all five primaries held on the same day.

Romney used the speech to declare he has swept all five states holding primaries Tuesday, saying "I can say with confidence and gratitude that you have given me a great honor and solemn responsibility, and together, we are going to win on November 6," referring to the polling day of the general election.

According to projections by major US TV networks, Romney has won primaries held Tuesday in Rhode Island, Connecticut, Pennsylvania and Delaware. He is also expected to win in New York. He faced no major opponents as his main rival Rick Santorum dropped out.

Romney used the speech to supporters in Manchester, New Hampshire, to attack the "failed leadership and faulty vision" of President Barack Obama, who he will face in November as he all but sealed the GOP nomination.

"Four years ago Barack Obama dazzled us in front of Greek columns with sweeping promises of hope and change. But after we came down to earth, after the celebration and parades, what do we have to show for three and a half years of President Obama?" Romney asked. "Is it easier to make ends meet? Is it easier to sell your home or buy a new one? Have you saved what you needed for retirement? Are you making more in your job? Do you have a better chance to get a better job? Do you pay less at the pump?"

As he attacked Obama, Romney also touted his credentials as an entrepreneur, promising reforms and change if he is elected into the White House.

"I have a simple message: Hold on a little longer. A better America begins tonight," said Romney.

Romney is pivoting to the general campaign mode as he solidifies the GOP field. After Santorum dropped out, Newt Gingrich, the former House speaker, also indicated earlier Tuesday he would "reassess" his struggling campaign.