Mitt Romney has told the Republican party convention in Florida that US President Barack Obama has failed to deliver the change he promised America.
Mr Romney used his speech to officially accept his nomination to challenge the Democratic president in November's election, saying hope had turned to disappointment and division.
The former governor of Massachusetts presented his plan involving energy independence, cutting the budget deficit and creating jobs, the BBC reports.
"I wish President Obama had succeeded because I want America to succeed," Mr Romney said, in a speech watched by millions in the United States.
"The time has come to turn the page. Today the time has come for us to put the disappointments of the last four years behind us. To put aside the divisiveness and the recriminations. Now is the time to restore the promise of America."
Mr Romney vowed to create 12 million American jobs over the next four years and turn around an economy saddled with an 8.3% unemployment rate. He pledged to make the US energy independent by 2020, cut the national deficit and negotiate new trade agreements.
He brought the crowd to its feet when he pledged to repeal Mr Obama's signature healthcare bill.
The 65-year-old also recounted details of his Mormon upbringing, with anecdotes about his family life and his parents' loving marriage.
Mr Romney talked about his own experiences as a father, apparently becoming emotional as he talked about the times when he and his wife Ann would wake up to find "a pile of kids asleep in our room".
The event ended with many members of the Romney family - his wife, five sons and their wives and most of his 18 grandchildren - on stage with him as thousands of balloons were released over the convention floor.