Speaking at a rally of thousands of people marking one month since a U.S. missile strike against a factory in the Sudanese capital, Khartoum, the president said the threat was made in an unsigned letter he received from the U.S. administration. He gave no details, but warned that his government would respond.
U.S. officials were not immediately available for comment.
A Sudanese parliamentary official said the alleged written threat from Washington was handed to el-Bashir by a former senior Sudanese official. The official, speaking on condition of anonymity, did not say when the message was received.
"Welcome to a second and third strike. But next time we will not go to the Security Council...We will reserve the right to respond and our response will be very painful," el-Bashir told the rally.
Washington claimed the plant produced chemical weapons agents.
But Sudan, which insisted the factory produced only pharmaceuticals, called for a U.N. Security Council investigation.
Mohammed el-Hassan Amin, head of the political section of the ruling National Congress party, said Saturday that the alleged U.S. message also accused Khartoum of hosting groups loyal to Saudi dissident Osama Bin Laden.
Washington also attacked what it called Bin Laden's training camp in Afghanistan, accusing the Saudi dissident of being behind the bombings of U.S. embassies in Kenya and Tanzania on Aug. 7.
El-Bashir pledged the destroyed plant would remain untouched as a reminder of the "American aggression."
Protesters burned a U.S. flag as verses from the Muslim holy book of Koran were read over loudspeakers.
A poster pasted to a truck depicted a donkey with a face of President Clinton with former White House intern Monica Lewinsky mounted on its back. Lewinsky is at the center of a sex scandal with Clinton.
Former U.S. Attorney General Ramsey Clark, who attended the rally, apologized for the U.S. missile strike and urged the United Nations to send an inspection team to determine whether the plant produced chemical weapons agents.
Written by Mohamad Osman.
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