In an interview secretly recorded in a Jakarta prison cell, Abu Bakr Bashir told Australia's Seven television network that any effort to attack the US was good, but the methods should be adapted to the situation.
The jailed Indonesian Muslim preacher's words - aired on Wednesday night - suggest the US should be fought with force in the Muslim world and politically in the US.
Speaking in Indonesian, Bashir said: "We have to oppose America physically in Afghanistan, Iraq and elsewhere. We have to oppose it physically, such as to bomb or do other things."
But he cautioned against attacking the US on its own soil: "Nowadays, we should not attack America with weapons, politics [is] enough."
On the Madrid attacks last week, Bashir said: "The people of Spain have put pressure on their government because in their opinion the bombings were caused by the government's support of America, and that was correct."
Likely to be freed next month, the preacher concluded: "My advice to all governments who support America is to retreat because they are supporting crimes."
"I am convinced that sooner or later that America and the countries that assist it will be destroyed by Allah."
Soon to be released
Intelligence agencies linked Bashir to al-Qaida and named him the spiritual leader of Jemaah Islamiya – which they accuse of carrying out the Bali blasts in October 2002 that killed 202 people.
JI is also blamed for a bomb attack at the J W Marriott Hotel in Jakarta last August that killed 12.
But the 65-year-old has consistently denied links to JI and Indonesian prosecutors did not implicate him in the Bali bombings.
Jailed for immigration offences, his lawyer told journalists on Thursday the Justice Ministry said he would be released on 30 April."