United Nations, December 21 (RHC)-- The UN envoy for Yemen says he is still "optimistic" that a fully-respected ceasefire will come into force in Yemen, despite several violations of a seven-day truce already in effect in the war-torn country.

Ismail Ould Cheikh Ahmed said at a press conference on Sunday after ending the peace talks that "incredible progress" has been made at the talks among Yemen's warring sides in Switzerland, adding that all sides agreed to hold the next round of talks on January 14th.

The negotiations began in the Swiss village of Magglingen on December 15th between a delegation representing the Houthi Ansarullah movement and representatives from Yemen's fugitive former president Abd Rabbuh Mansour Hadi to end the war.

The UN envoy also noted that the UN experts knew from the beginning that there would be violations of ceasefire, saying: "We have to remember that it is a war that went back for more than nine months. Ceasefire is difficult but this is our request."

The UN envoy stressed that the conflicting parties who attended the talks agreed that the main objective is to "end this war and have permanent ceasefire."

Ould Cheikh Ahmed further said that some 102 trucks carrying humanitarian aid arrived in conflict-stricken Tai0zz province and that both sides agreed on the need to "lift all forms of blockade and allow safe, rapid and unhindered access for humanitarian supplies" to all affected areas.