Republican presidential hopeful Mitt Romney has secured his party's nomination to run for the highest office in the United States.

Republican party delegates from across the country cast more 1,144 votes for Mr. Romney, the former Massachusetts governor, during a roll call late Tuesday.

Former New Hampshire governor John Sununu started the formal nomination process Tuesday, calling Mr. Romney “the right man at the right time,” saying he “knows how to fix the unfixable.”

Fellow Republican presidential candidate, Texas Representative Ron Paul, also received some votes.

Mr. Romney arrived at the convention in the city of Tampa, Florida Tuesday. His wife, Ann, speaks later in the evening. New Jersey Governor Chris Christie closes the night with his keynote address.

On the flight to Florida, Mrs. Romney told reporters she will speak from the heart about her husband of 43 years.

“You will see that my speech is heartfelt. I think a lot of you have been covering me long enough that you know that I have never gone off of a written text, so this is a unique experience for me.”

Party officials are hoping Mrs. Romney's speech will showcase a more personal side of the Republican candidate than the image the Obama campaign has painted of him as a wealthy businessman who has little connection with everyday Americans and their economic concerns. Christie is expected to pinpoint what Republicans see as the significant failures of Mr. Obama's tenure over the last three-and-a-half years.

Tuesday has been the first full day of the Republican convention, with most events canceled Monday as Tropical Storm Isaac skirted Florida's western coastline before becoming a hurricane. Convention officials are still watching the storm's path as it heads toward the northern coast of the Gulf of Mexico for a possible landfall late Tuesday or early Wednesday in Louisiana and it could again force changes in the convention schedule.

The Republican governor of Louisiana, Bobby Jindal, canceled his planned convention speech, saying he was staying home to deal with the prospect of Isaac hitting his state.

An opinion poll published Monday in The Washington Post shows President Obama, the Democratic incumbent, and Mr. Romney in a tight contest. It says Mr. Romney has the support of 47 percent of likely voters, compared to 46 percent for Mr. Obama — little changed from early July's figures.

Mr. Obama is spending Tuesday and Wednesday campaigning in college towns in Iowa, Colorado and Virginia. The Democrats hold their convention next week in Charlotte, North Carolina.