LOS ANGELES (REUTERS) - Three former US secretaries of state - Hillary Clinton, Colin Powell and Madeleine Albright - will make guest appearances in October on political television drama Madam Secretary, broadcaster CBS said on Tuesday (July 24).

The three have already filmed their episode, which involves fictional Secretary of State Elizabeth McCord, played by Tea Leoni, turning to her more experienced peers for advice when the series returns for a fifth season on Oct. 7.

"It was a privilege to experience their perspectives and discourse both in and behind the scenes," Barbara Hall, creator and executive producer of Madam Secretary, said in a statement.

Madam Secretary portrays McCord's efforts to balance delicate diplomatic issues as well as personal stories and her family life.

The show launched in 2014, a year after Clinton stepped down from her post at the State Department after four years. In 2015, the Democrat declared she would run for president in 2016 but was defeated by Republican Donald Trump.

Clinton has appeared briefly on entertainment shows as herself, including a cameo on comedy Broad City in 2016 and with Saturday Night Live doppelganger Kate McKinnon in 2015.

Madeleine Albright, the first female secretary of state, served under Democratic President Bill Clinton. Colin Powell, secretary of state under Republican President George W. Bush, was the first black man to hold the post.

The new season of Madam Secretary will be premiering on Sony Channel (Singtel TV Channel 316, StarHub TV Channel 510) on Oct 8 at 8.55pm.