Former US president George W Bush called the killing of al-Qaeda leader Osama bin Laden an "unmistakable message" of justice and praised the US military and intelligence communities for the achievement, DPA reported.
"The fight against terror goes on, but tonight America has sent an unmistakable message: No matter how long it takes, justice will be done," Bush said in a statement released by his spokesman.
Bush launched the massive hunt for bin Laden following the September 11, 2001 terrorist attacks, declaring that he wanted him "dead or alive." But Bush left office in January 2009 without successfully killing or capturing bin Laden.
Bush said Obama telephoned him earlier to inform him that a US special forces killed bin Laden in a firefight in Pakistan.
"I congratulated him and the men and women of our military and intelligence communities who devoted their lives to this mission. They have our everlasting gratitude," he said.
"This momentous achievement marks a victory for America, for people who seek peace around the world, and for all those who lost loved ones on September 11, 2001," he added.