The US government turned up the pressure on the head of a small church who plans to burn copies of the Koran on September 11, warning him that doing so could endanger US troops and Americans everywhere.
But the Reverend Terry Jones insisted he would go ahead with his plans, despite criticism from the top US general in Afghanistan, the White House and the State Department, as well as a host of religious leaders.
Mr Jones, who is known for posting signs proclaiming that Islam is the devil's religion, said the US Constitution gives him the right to publicly set fire to the book that Muslims consider the word of God.
General David Petraeus warned that "images of the burning of a Koran would undoubtedly be used by extremists in Afghanistan - and around the world - to inflame public opinion and incite violence".
It was a rare example of a military commander taking a position on a domestic political matter.
Mr Jones responded that he is also concerned but is "wondering: 'When do we stop'?"
He refused to cancel the protest set for Saturday at his Dove World Outreach Centre in Florida, a church that espouses an anti-Islam philosophy.
"How much do we back down? How many times do we back down?" Mr Jones said. "Instead of us backing down, maybe it's to time to stand up. Maybe it's time to send a message to radical Islam that we will not tolerate their behaviour."
Still, Mr Jones said he will pray about his decision.
State Department spokesman P.J. Crowley said the administration hoped Americans would stand up and condemn the church's plan.
"We think that these are provocative acts," Mr Crowley said. "We would like to see more Americans stand up and say that this is inconsistent with our American values; in fact, these actions themselves are un-American."
Meeting with religious leaders to discuss recent attacks on Muslims and mosques around the US, Attorney General Eric Holder called the planned burning both idiotic and dangerous, according to a Justice Department official.
Secretary of State Hillary Clinton added her disapproval at a dinner in observance of Iftar, the breaking of the daily fast during the Muslim holy month of Ramadan.
"I am heartened by the clear, unequivocal condemnation of this disrespectful, disgraceful act that has come from American religious leaders of all faiths," Mrs Clinton said.
At the White House, spokesman Robert Gibbs echoed the concerns raised by Mr Petraeus. "Any type of activity like that that puts our troops in harm's way would be a concern to this administration," Mr Gibbs told reporters.
Mr Jones said he has received more than 100 death threats and has started wearing a .40-calibre pistol strapped to his hip.
The 58-year-old minister said the death threats started not long after he proclaimed in July that he would stage International Burn-a-Koran Day. Supporters were mailing copies of the Islamic holy text to his church to be incinerated in a bonfire.
Mr Jones, who has about 50 followers, gained some local notoriety last year when he posted signs in front of his small church declaring "Islam is of the Devil".