By Reuters

More than 1.5 million people have fled Syria as conditions there deteriorate rapidly, the United Nations refugee agency (UNHCR) said Friday in Geneva.

The exodus has accelerated over the past four months and the agency estimates that almost one million refugees have registered since January, UN officials said.

"The fact that more than 1.5 million have registered or have appointments with UNHCR sadly means the actual number is much higher," UNHCR said in a statement, without giving an estimate for the total.

"Refugees tell us the increased fighting and changing of control of towns and villages, in particular in conflict areas, results in more and more civilians deciding to leave," it said.

Most of the refugees have fled to neighbouring Lebanon and Jordan where UNHCR said it had counted 470,457 and 473,587 respectively this week.

Syria's population is 23 million.

The Associated Press reported Friday that a six-member UN team led by a former Syrian planning minister is drawing up a comprehensive postwar reconstruction plan, even as the country's civil war rages on with no apparent end in sight.

A joint U.S.-Russian push to bring together Syria's political opposition and representatives of President Bashar al-Assad's regime to negotiate a peaceful transition has given their work new urgency.In a rare interview, the U.S.-educated economist, Abdullah al-Dardari, told The AP that more than two years of fighting have cost Syria at least $60 billion US and caused the vital oil industry to crumble. A quarter of all homes have been destroyed or severely damaged, and much of the medical system is in ruins.

Now, he says, the Syrians have to be ready to rebuild when the fighting ends. He says his team has been overwhelmed with requests for a reconstruction plan to support the U.S.-Russian initiative on the off chance it succeeds.

"I see a glimmer of hope," said al-Dardari, who now works for a Beirut-based UN development agency. "There appears to be more readiness for a political compromise by different groups in the opposition and by officials in the government."

With files from The Associated Press