United Nations humanitarian chief Valerie Amos will visit Syria and Lebanon to discuss ways to increase emergency aid to civilians affected by the Syrian conflict, UN spokesman Eduardo del Buey said on Monday.

Amos will fly to Syria on Tuesday, where she will discuss relief efforts for civilians caught up in the conflict, del Buey said.

She will then travel to neighboring Lebanon – where some 37,000 Syrians have taken shelter, according to the United Nations – to meet with refugees and discuss the situation with officials and representatives of non-governmental organizations.

More than 17,000 people have been killed in Syria since the outbreak of protests against President Bashar al-Assad in March 2011, according to UN estimates.

More than 150,000 Syrian refugees have officially registered in four neighboring countries – Lebanon, Jordan, Iraq and Turkey, while officials acknowledge that the real number of refugees is likely to exceed 200,000.