The aim of the mission is to spotlight the long-standing plight of over 100,000 Bhutanese refugees who have been living in seven camps in eastern Nepal since the introduction of strict citizenship laws in their homeland 16 years ago.
During his time in Nepal - High Commissioner António Guterres' first official visit to the Himalayan country - he will visit one of the refugee camps and meet with Government authorities, UN agencies and donors.
"UNHCR has been very encouraged by the efforts of a group of interested countries to assist in resolving this protracted situation," the agency's spokesperson Jennifer Pagonis told reporters in Geneva last week.
On Thursday, Mr. Guterres will head to Bhutan to hold talks with officials there.
Frustration has been growing among the refugees, who are unable to work outside the camps in which they reside, as they have seen no solution to their situation since arriving in Nepal in the early 1990s.
Last November, UNHCR and the Nepalese Government began taking a census of refugees, in which any existing information will be validated, cross-checked, updated and recorded in a new database, and refugees will have their photographs taken for identity cards.