Syrian President Bashar al-Assad stood firm Sunday against global calls for him to step down, insisting that his vision should be the foundation of any future solution to the country's crisis.

In a rare public speech, al-Assad lambasted those who want to "fragment Syria" and accused foreigners of helping fuel terrorism on the ground.

"Those are the enemies of the people and the enemies of God. And the enemies of God will go to hell," the president told a packed auditorium of supporters.

Al-Assad laid out a plan for a solution to the crisis, which he said should start with regional countries ending their support for "terrorists." The government frequently describes dissidents as terrorists.

The president's plan includes a national dialogue as well as the writing of a new constitution that would be put up for a public referendum.

But there's a major caveat to the plan: Al-Assad said he will not deal with "terrorists" -- a description that, in his view, includes the vast majority of the opposition.

Similarly, opposition members have said they will not work directly with al-Assad's "criminal" government, nor will they accept any solution that doesn't involve al-Assad's departure.

"There can be no solution to the conflict in Syria until he is pushed out with his team. His speech is continuing the war against the Syrian people," said George Sabra, vice president of the National Coalition of Syrian Revolutionary and Opposition Forces.

In a statement, the opposition coalition described the speech as a "preemptive strike against both Arab and international diplomatic solutions."

Al-Assad is incapable of coming up with a viable political solution to the crisis, the opposition coalition said, because he insists on remaining in power "despite being rejected by his people and his traditional allies."

But just as he has throughout Syria's 22-month uprising, al-Assad refused to acknowledge the widespread movement inside his country seeking an end to four decades of his family's rule.

He claimed many of the opposition fighters are not Syrians, but rather foreign terrorists bent on destabilizing the nation.

"We are facing an external attack against us, which is more dangerous than any other previous wars," he said.

"We are dealing with those who are extremists, who only know the language of killing and criminality."

British Foreign Secretary William Hague described al-Assad's speech as "beyond hypocritical."

"Deaths, violence and oppression engulfing #Syria are his own making, empty promises of reform fool no one," Hague tweeted.

Similarly, U.S. State Department spokeswoman Victoria Nuland criticized al-Assad's speech, saying it was "yet another attempt by the regime to cling to power and does nothing to advance the Syrian people's goal of a political transition."

Al-Assad has "lost all legitimacy and must step aside," she said.

As the president spoke, the violence carried on unabated.

"I have heard 10 shells fall during the speech," resident Mohammed Doumany told CNN from Douma, a suburb of Damascus.