The British government said it had launched a large-scale evacuation of its citizens from Sudan on Tuesday, after the North African country's warring factions agreed to a 72-hour ceasefire.
Britain said military flights would depart from an airfield outside Khartoum, and would be open to those with British passports. Priority will be given to family groups with children, the elderly and individuals with medical conditions.
"The government has begun a large-scale evacuation of British passport holders from Sudan on RAF flights," Prime Minister Rishi Sunak said on Twitter. "I pay tribute to the British Armed Forces, diplomats and Border Force staff."
Foreign Secretary James Cleverly said the government had started contacting nationals directly and providing routes for departure out of the country, Reuters reported.
On Monday, the government estimated around 4,000 British nationals were in Sudan and armed forces minister James Heappey said there was a military team in the east of the country doing reconnaissance on possible options for helping Britons leave.
The Foreign Office said on Tuesday British nationals should not make their way to the airfield unless they were called, and warned the situation remained volatile, meaning the ability to conduct evacuations could change at short notice.
The British armed forces evacuated diplomatic staff and their family members from Sudan on Saturday and the government had come under criticism from British citizens still stuck there that they were not doing enough to help others get out.
Britain said it was working with its international partners to arrange the departure and would also continue to look at other potential options for helping British nationals leave Sudan.