Khartoum - Sudan said on Monday that its decision to make Egyptian men aged from 18 to 50 obtain entry visas was aimed at preventing "terrorists" from infiltrating the country.
Since 2004 Egyptians have enjoyed visa-free access to Sudan, but on Friday Sudanese authorities made it mandatory for adult Egyptian men to obtain visas before entering the country.
Egyptian women are still allowed to enter without visas.
"The decision of imposing visas for Egyptians was taken after consultations between the two countries," Sudanese Foreign Minister Ibrahim Ghandour told reporters.
"It aims to ensure organised entry of citizens in both countries and to prevent terrorist elements from entering."
While Egyptians went visa-free under a deal signed between the two countries in 2004, Sudanese nationals had to obtain visas for entering Egypt.
Sudanese media reports say Khartoum's decision may have been triggered following the arrests of several Arab nationals after a blast in an apartment in the capital in February.
One man was wounded in the blast while assembling explosives in the apartment.
Sudan is home to tens of thousands of Syrians who have arrived in the east African country since their nation's brutal civil war erupted in 2011.
Officials have regularly claimed to be stepping up efforts to fight extremism in the region, although Washington continues to list Sudan as an alleged state sponsor of terrorism since 1993, a charge Khartoum steadfastly denies.