WASHINGTON (AFP) - The family of James Foley, the US reporter murdered by Islamist militants in Syria, launched a foundation in his name on Friday to support kidnap victims, frontline journalism and inner-city youth.

Mr Foley's parents John and Diane announced the James W. Foley Legacy Fund with full-page ads in major newspapers and on the new foundation's website, four weeks after his death.

Mr Foley - a freelancer who had reported for GlobalPost, Agence France-Presse and other outlets from Afghanistan, Libya and Syria - was kidnapped in November 2012 in northern Syria.

Last month, militants from the so-called "Islamic State" triggered worldwide revulsion by releasing video footage of his murder, which they declared was to avenge US air strikes against their group.

On Friday, his family issued a plea for donations to build a foundation to fund the good works he supported in his lifetime, writing: "Jim did not die in vain. Please help us build on his memory." "Jim and his family, like many other US hostages and their families, have experienced the devastating consequences of inconsistent, opaque, and unaccountable policies of governments in hostage situations. This has to change," the site says.

During Mr Foley's captivity he was held alongside more than a dozen foreign hostages. Several Europeans were freed alive, allegedly after ransoms were paid to the Islamic State.

The United States and Britain say they do not pay ransoms to groups they regard as terrorists.

Mr Foley and fellow US hostage Steven Sotloff were killed and British captive David Haines has been threatened with death.

"We will form a resource center and support network for US hostage families," wrote the Foleys, who this week complained that the United States had not done enough to save their son.

They called for "an international dialogue to establish a standard world-wide policy for kidnapping prevention and resolution." In addition to working for hostages, the legacy fund will work with existing watchdogs like the Committee to Protect Journalists and Reporters Without Borders to help frontline reporters.

And, in honour of the four years Mr Foley spent working with inner-city youth as a teacher before becoming a reporter, the foundation will support inclusive teaching initiatives.