The Trainspotting star is a longtime ambassador of the global welfare charity, and he's spoken out to highlight the latest humanitarian crisis facing the region.
In the clip, being aired on U.K. TV this month (Apr12), McGregor urges his fans to donate cash to the cause, saying, "Children in west Africa are at risk from (sic) starving to death. Drought, rising food prices, and a harvest devastated by insect plague have created a humanitarian crisis on the verge of a disaster.
"Over one million children are at risk from (sic) starving to death. But we can stop these children from dying... Children need your help and they need it now."
McGregor has previously fronted UNICEF campaigns for aid in flood-ravaged Pakistan and drought-hit east Africa.