The number of refugees who have fled Syria has reached more than 250,000, the United Nations said Tuesday, calling the humanitarian problems sparked by the conflict \"our biggest crisis\". \"Syria ... is our biggest crisis at the moment ... Latest figures show that more than a quarter of a million Syrian refugees (253,106 people) have now been registered in the surrounding region, or are awaiting registration,\" U.N. Refugee agency spokesman Adrian Edwards said. \"The speed with which people are fleeing the country ... is an extraordinary acceleration of the crisis,\" he added. In Jordan, where the UNHCR\'s High Commissioner Antonio Guterres is accompanying the agency\'s Special Envoy, actress Angelina Jolie, there are 85,197 registered refugees, with a further 35,961 awaiting processing. Jolie arrived in Jordan on Monday evening accompanied by a Jordanian military escort. She visiteddisplaced Syrian families who recently crossed the border. She is due to visit the Al-Zaatri refugee camp later Tuesday and then King Abdullah of Jordan, Prime Minister Fayez Tarawneh and foreign affairs minister Nasser Judeh. Meanwhile, the World Health Organization said it was seeking to reinforce its activities in Homs, where medical care was in a critical state and hospitals were \"overwhelmed with patients\".