Sudan has rejected a U.S. request to send a platoon of Marines to bolster security at the U.S. embassy outside Khartoum, the state news agency SUNA said on Saturday.
On Friday, around 5,000 people protested against a film that insults the Prophet Mohammad, storming the German embassy before breaking into the U.S. mission.
They also attacked the British embassy. At least two people were killed in clashes with police, according to state media.
A U.S. official told Reuters on Friday that Washington would send Marines to Sudan to improve security at the embassy, which is located outside Khartoum for security reasons.
"Sudan is able to protect the diplomatic missions in Khartoum and the state is committed to protecting its guests in the diplomatic corps," Sudanese Foreign Minister Ali Ahmed Karti told SUNA.
The U.S. State Department declined to comment.
Sudan beefed up security at some missions on Saturday. A riot police truck was parked in front of the deserted German embassy, which protesters had set on fire on Friday. An Islamic flag raised by the crowd was still flying. Three officers manned the main gate.
More than 20 police officers were sitting in front of the U.S. embassy.
The film, which depicts Mohammad as a womanizer and charlatan, was made in the United States, and Muslim outrage has led to crowds assaulting U.S. diplomatic missions in a number of Arab countries.
Sudan has also criticized Germany for allowing a protest last month by right-wing activists carrying caricatures of Mohammad, and for Chancellor Angela Merkel's award in 2010 to a Danish cartoonist who had depicted the prophet, triggering unrest across the Islamic world.
President Omar Hassan al-Bashir has been under pressure from Islamists who feel the government has given up the religious values of his 1989 Islamist coup.
The Sudanese government had called for protests against the film, but peaceful ones. U.S. President Barack Obama's administration said it had nothing to do with the movie, which is little more than an amateurish video clip and appears to have been made in California.