US Secretary of State John Kerry on Tuesday hailed the announcement of a 72-hour truce in Yemen starting later this week, and called for its "unconditional renewal."

The cessation of hostilities between Yemeni forces and their Saudi backers, and Huthi rebels and allied forces loyal to ousted president Ali Abdullah Saleh, is due to take effect Thursday.

"This cessation requires all parties to implement a full and comprehensive halt to military activities of any kind, and help facilitate the delivery of humanitarian assistance to Yemenis across the country," Kerry said in a statement.

"We ask the parties to take all steps necessary to advance the implementation of this cessation, call on them to sustain it, and strongly encourage its unconditional renewal."