LOS ANGELES - THE ex-wife of Michael Jackson vowed on Thursday to fight for custody of the two children she had with the pop icon, setting the stage for a bitter legal battle with the late star's family.

The station reported on its website that Ms Rowe had said she was willing to submit to any testing, including DNA, to prove she was the biological mother of Prince Michael, 12, and Paris, 11.

'I am stepping up,' Ms Rowe added. 'I have to.' Ms Rowe, who was married to Jackson for three years from 1996, also said she was willing to undergo psychological testing in any custody claim.

NBCLA said Ms Rowe would also seek a restraining order to keep Jackson's father, Joe Jackson, away from the children.

Ms Rowe has been largely silent since the sudden death of Jackson, 50, on June 25 from an apparent cardiac arrest.

On Monday, a Los Angeles court named the star's 79-year-old mother Katherine Jackson as the temporary guardian of Prince Michael, Paris and younger brother Prince Michael II, who was born to a secret surrogate.

A 2002 will filed in Los Angeles Superior Court on Wednesday revealed that Jackson wanted his mother to gain custody of his children in the event of his death, with soul legend Diana Ross named as a back-up guardian.

Ms Rowe signed away her parental rights to her two children in 2001, describing Jackson as a 'wonderful man... a brilliant father.' However a Los Angeles judge reversed the order in 2004 after Ms Rowe cited concerns over publicity related to Jackson's prosecution for child molestation.

Ms Rowe later settled the case with Jackson, reportedly securing visitation rights to the children. -- AFP