JUBA, Sudan, April 12 (Xinhua) -- Former U.S. President Jimmy Carter on Monday described the beginning of the polling process in Sudan's elections as difficult.

Speaking to reporters at the Juba airport, Carter said the elections were supposed to begin on Monday instead of Sunday to allow the Sudanese National Elections Commission (NEC) to complete its logistical preparations.

Carter arrived in south Sudan on Monday to get acquainted with progress of the polling process in the region.

He visited the Attla Barra polling station in Juba and expressed hope that the voters would be able to vote under natural circumstances.

Carter is expected to visit polling stations outside Juba to get acquainted with progress of the polling process.

He said he would meet President of southern Sudan government, Salva Kiir Mayardit and Chairman of the national elections commission in the south and listen to reports of his center's observers in the region.

The Sudan People's Liberation Movement (SPLM) on Sunday criticized what it termed as mistakes during the first day of the polling in the south and demanded extension of the polling days to enable around 4 million southern Sudanese voters to cast their votes.