The three-day truce brokered by the United Nations went into effect on Wednesday midnight with an aim to facilitate humanitarian aid to the war-stricken cities.
"The ceasefire was largely holding despite reported violations from both sides in several areas," said Ould Cheikh Ahmed in a statement released on Saturday, adding that over the last days, UN personnel were able to reach areas that were inaccessible to deliver food and aid.
"We would like to build on this and we aim for a wider outreach in the next few days," he added, Xinhua reported.
The situation in Yemen has deteriorated since March 2015 when a Saudi-led Arab coalition started airstrikes against Yemen to restore power to the fugitive former government after Houthis captured the capital city of Sana’a.
Houthis hold most of Yemen's northern regions while the fugitive government forces backed by Saudi-led military coalition control the rest of the country, including seven southern provinces.
The war has killed more than 10,000 people, half of them civilians, injured more than 35,000 others and displaced over 2 million, according to humanitarian agencies, with Saudi Arabia facing global condemnations for targeting civilian infrastructures.