"The Department urges U.S. citizens to defer travel to Yemen and those U.S. citizens currently living in Yemen to depart," the statement read.
The department also confirmed that it had suspended embassy operation in the Yemeni capital "due to the deteriorating security situation in Sanaa."
The notice superseded the previous travel warning for Yemen issued by the US State Department in September 2014.
The Houthis, Yemeni Shiite opposition group, first staged massive protests against injustice on the part of the Yemeni government last August. They took over a number of cities, including Sanaa, prompting the US-backed president to resign.
After months of sectarian clashes, the Houthis dissolved the country's parliament last week and declared that the Revolutionary Committee, the group's security arm, would govern Yemen.
