Today (bbc).
In a statement, UN humanitarian chief Valerie Amos stressed the importance of "unhindered access to identify urgent needs and provide emergency care and basic supplies".

"There is no time to waste," she said.

The UN's announcement came after a coalition of 200 aid and rights groups called on Russia and China to support United Nations' attempts to end the violence in Syria.

At the political level, Russia and China have both blocked UN Security Council resolutions on Syria.