The International Committee of the Red Cross expressed alarm last week after heavy fighting erupted between Houthis, a Shiite movement, and military forces in Dammaj, a city in northern Yemen.
Karen Sasahara, the U.S. charge d'affaires in Yemen, said the Houthis are called on to play a role in charting Yemen's future.
"We believe they are a part of the Yemeni society and encourage their participation in the national dialogue conference," she was quoted by Yemen's official Saba New Agency as saying Tuesday. "We call on them to be a political group and not armed militants."
Houthis this week agreed to halt the fighting. The group launched a rebellion against the government in 2004.
Yemen has since struggled to maintain a sense of national security because of the threat from al-Qaida, southern secessionist movements and the northern rebellion. Yemeni President Abdu Rabbo Mansour Hadi said there are more than 500 delegates tackling national reconciliation issues in the country.
The U.S. Embassy in Yemen remains closed for regular services because of terrorism threats that surfaced early this year.