The mission comes as the Syrian insurgency enters its second year, rebels try to oust President Bashar Assad and Assad's military engages in bloody crackdowns against rebel troops and civilians. CNN reported a number of world powers are pushing for entry into the country to provide humanitarian relief.
U.N. Undersecretary-General for Humanitarian Affairs Valere Amos said Syrian officials will lead a mission to the provinces of Homs, Hama, Tartous, Latakia, Aleppo, Deir Ezzor, Rif Damashq and Dara'a.
Amos said United Nations and Organization of Islamic Cooperation officials will go along, CNN reported.
"It is increasingly vital that humanitarian organizations have unhindered access to identify urgent needs and provide emergency care and basic supplies. There is no time to waste," Amos said in a written statement.
Syrian ally Iran said said it sent medicine and medical equipment to Syria, Iranian media reported. CNN said a plane carrying 40 tons of aid arrived in Damascus.
Meanwhile, thousands of Syrians congregated at a central square in Damascus Thursday in what the government said was a march for Syria and against the year-old uprising.
Opposition leaders said the Syrian government ordered people to go to work on a national holiday so it would be easier to bus state employees and students to the rally, The New York Times reported.
The holiday, Teachers' Day, was on the one-year anniversary of mass demonstrations in the southern city of Dara'a that turned sporadic protests against the government of President Bashar Assad into a national uprising. Assad responded brutally, charging the uprising was led by terrorists, thugs and foreigners.
The rally came as Syria's military intensified its northern offensive Thursday after all but taking over the city of Idlib, the second opposition stronghold besieged in two weeks.
Witnesses said the crowd cheered as the flags of Syria, Russia -- the country's main arms supplier -- and Hezbollah, the militant Islamic group supporting Assad, waved alongside each other.
The pro-Assad rally came after government forces drove back rebels from strongholds in the north and swept through Dara'a as international efforts to end the violence appeared to stall and disagreements among exile opposition leaders became public, the Times said.
U.N.-Arab League Joint Special Envoy for Syria Kofi Annan, seeking to end the yearlong bloodshed, said he received a communication from aides to Assad asking for clarification of the proposals Annan made in Damascus meetings during the weekend.
"But given the grave and tragic situation on the ground, everyone must realize that time is of the essence," spokesman Ahmad Fawzi said in a statement from Geneva, Switzerland.
"This crisis cannot be allowed to drag on," he said.
Annan is due to brief the U.N. Security Council Friday.