London, May 9 -- Teen pop sensation Selena Gomez, who is a UNICEF ambassador for the past threeyears, has vowed to restrict her daily expenses to just $1.50 for the entire week to help poor Africankids. The singer has also shot an emotional video for UNICEFs Live Below the Line Campaign urgingpeople to help children of Sahel region who are starving due to a severe drought, Contactmusicreported. "In a continued effort to help support Sahel...I am living off of 1.50 a day (this week). 1.4Billion people live on USD 1.50 per day their whole lives, we only need to do it for one week. Can you doit? Join UNICEF... in the Live Below the Line Campaign and help provide children food and supplies to the drought effect region of the Sahel," Selena wrote on her Facebook wall.