Bush's reported remarks come after Dick Cheney, his former vice-president, strongly criticised Barack Obama, Bush's successor, for repudiating the use of torture on suspects held in US facilities such as the US prison camp in Guantanamo Bay, Cuba.
Cheney said last week that he remained a "strong proponent" of what he described as the US's "enhanced interrogation programme" including the use of "waterboarding", which has been widely denounced as torture by human rights groups.
He also dismissed the "contrived indignation and phony moralising" of those who opposed it and said such methods were driven by a need to prevent further attacks following those on September 11, 2001, in which about 3,000 people died.
"The [Obama] administration has found that it's easy to receive applause in Europe for closing Guantanamo ... but it's tricky to come up with an alternative that will serve the interests of justice and America's national security," he said.
Setback for Obama
Obama defended his decision to close Guantanamo Bay by January next year, saying last week that it had probably "created more terrorists around the world than it ever detained".
He also said his administration was being forced to clean up a situation "that is quite simply a mess".
"As commander-in-chief, I see the intelligence, I bear the responsibility of keeping this country safe and I categorically reject the assertion that these [the camp and military tribunal system] are the most effective ways of keeping this country safe," he said.
His comments followed a setback for his administration in its efforts to close the camp after US Congress refused to sanction $80m the White House was seeking for the shutdown of Guantanamo until Obama decides what to do with the facility's inmates.
The senate's rejection was particularly stinging for the president as Congress is controlled by members of Obama's Democratic party.
Legislators rebelled largely over concerns that some of the Guantanamo inmates could be jailed, or even released, in the US and amid Republican threats to brand the administration as being "soft" on national security.