WASHINGTON (AFP) - The US Senate has unanimously approved a Bill providing up to US$10 million (S$12.6 million) for information leading to the arrest or conviction of people involved in executing two American journalists murdered by jihadists.

"One way we can honour the memories of James Foley and Steven Sotloff is to bring their evil murderers to justice, which this measure will help do," Senator Marco Rubio said Friday.

Rubio, from Sotloff's home state of Florida, said it was important to send the message "that the United States will work tirelessly to ensure that the deaths of these beloved journalists do not go unpunished."

Extremists from the Islamic State group, which has taken over swathes of territory in Iraq and Syria, published graphic videos in August and September showing the beheadings of Foley and Sotloff.

"Our country lost two of its own, and we must do everything possible to bring the terrorists who committed these atrocities to justice," said Senator Jeanne Shaheen.

The measure would authorise the secretary of state to provide the money under the State Department's Rewards for Justice programme, which was established in 1984.

The Bill would need to pass the House of Representatives before it goes to President Barack Obama for his signature.

However, this is unlikely to happen until after November's mid-term elections, because Congress has just begun a seven-week recess.