WASHINGTON, USA (AFP) — Republican leaders yesterday named Condoleezza Rice as a headline speaker at the party's convention, damping down speculation the former top diplomat could be a shock pick as Mitt Romney's running mate.

Rice, who served former president George W Bush and was the first African American woman to be secretary of state, remains popular among Republicans, though her stance on abortion conflicts with core conservatives.

The announcement was taken as a sign that Rice, who has said she has no desire to enter elective politics, will not be on the Republican ticket headed by Republican presumptive nominee Romney.

But plenty of big Republican names were not mentioned, including those of Florida Senator Marco Rubio, Ohio Senator Rob Portman and former Minnesota governor Tim Pawlenty, sparking speculation they are on Romney's shortlist.

Romney is expected to announce his running mate within days.

A vice presidential nominee gets his or her own moment in the spotlight at the convention, and the eventual pick is unlikely to be among speakers named at this early stage.

The vice presidential selection process causes frenzied speculation and some analysts suggested that Rice could help Romney improve his standing among women and pry a few African American voters away from Obama.

But she said in 2008 she "mildly" supported abortion rights, a stand that makes her unacceptable to many social conservatives who already harbour suspicions towards Romney.

The Republican National Committee also said yesterday that other speakers at this year's party convention in Tampa, Florida starting on August 27, would include the party's defeated 2008 nominee Senator John McCain.

Popular former Arkansas governor Mike Huckabee, current Ohio Governor John Kasich, South Carolina Governor Nikki Haley and Florida governor Rick Scott were also confirmed Monday as speakers at the convention.

New Mexico Governor Susana Martinez, the first female Hispanic governor in the US, will also make a speech, in a bid to reach out to a crucial voting demographic which currently favours President Barack Obama.

"We are proud and excited to announce these outstanding leaders will address the nation during our convention in Tampa," said RNC Chairman Reince Priebus.

"They are some of our party's brightest stars, who have governed and led effectively and admirably in their respective roles.

"Ours will be a world class convention, worthy of the next president of the United States."

President Barack Obama will accept the Democratic nomination for November's election at his party's nominating convention in Charlotte, North Carolina, starting on September 3.