This request is based purely on humanitarian grounds, amid a growing risk of famine in Yemen, the Office said in a note to correspondents on Friday in response to queries about Yemen.
"We welcome the decision of the US to strengthen its diplomatic engagement in support of the UN-led efforts to find a negotiated, comprehensive political solution to end the conflict in Yemen," Xinhua news agency quoted the note as saying.
"This is a positive development that could create further momentum for dialogue."
UN Special Envoy Martin Griffiths looks forward to working constructively with all parties at this critical time for the Yemeni people, it said.
On January 11, former Secretary of State Mike Pompeo said the US will designate Yemen's Iran-backed Houthi rebels as a foreign terrorist organisation over its role in the ongoing conflict in the impoverished country.
Also on Friday, the UN also welcomed all decisions seeking to create further space for dialogue and to alleviate the suffering of the Yemeni people.
Last week, new US Secretary of State Antony Blinken said last week that his team was reviewing the designation.
President Joe Biden said on Thursday that the US is ending its support for offensive operations in the Yemen conflict and that his country would step up diplomacy and support UN-led initiative to end the war.
"We are ending all American support for offensive operations in the war in Yemen, including relevant arms sales," the President said in his first major foreign policy speech since taking office last month.
According to figures released by the UN in December 2020, more than 230,000 Yemenis have died in the six-year-old war, mostly because of a lack of food, health services and infrastructure.
The Houthi militia has intensified attacks on the Yemeni government-held cities in the past year that killed and injured hundreds of people, according to the government of the war-torn country.
Yemen has been mired in civil war since late 2014, when the Houthi rebels seized control of northern provinces and forced the internationally-recognized government of President Abd-Rabbu Mansour Hadi out of the capital Sanaa.
The Saudi-led Arab coalition intervened in the Yemeni conflict in 2015 to support Hadi's government.