The mother of the American journalist killed by ISIS militants says her family feels let down by the U.S. government.

Speaking to CNN's Anderson Cooper, Diane Foley said she is "embarrassed and appalled" by how the U.S. government dealt with her son's case.

Diane Foley, speaking out for the first time since her son James Foley was beheaded by militants in mid August, said she thinks the government could have done more to free her son.

Officials told Foley family members "not go to the media," and that the "government would not exchange prisoners," or carry out "military action" to try to rescue her son.

Diane Foley said her family was told many times that raising ransom "was illegal (and) we might be prosecuted."

She added she hopes the government learns from her son's death and reacts differently if a similar situation arises in the future. Foley was the first of two American journalists killed recently.

Susan Rice, U.S. Ambassador to the United Nations, responded to Diane Foley's comments, saying the Obama Administration worked hard to free James Foley, saying they even launched a rescue mission involving hundreds of personnel.