The talks, in which a delegation of top Obama administration officials participated, were the first direct talks with representatives of the group since hostilities in Yemen began. The meeting was first reporting by The Wall Street Journal.
The discussions were held in neighboring Oman, whose leader, Sultan Qaboos bin Said, helped to arrange the talks. U.S. officials helped arrange a flight for several Houthi representatives to Oman's capital city of Muscat for the meeting, the sources said.
The U.S. officials said the Obama administration had been trying to open a channel of communication with the Houthi rebels for some time but until now had only been talking through intermediaries.
Last week's talks, led by Assistant Secretary for Near Eastern Affairs Anne Patterson and U.S. Ambassador to Yemen
Matthew Tueller, were aimed at putting a permanent ceasefire in place along with a political resolution to the conflict, which has drawn in Saudi Arabia and other Gulf states.
A senior administration official said U.S. officials from the embassy in Yemen
met with Houthi representatives several years ago in a more informal format, but that they have not had direct contact since then, let alone talks resembling the high-level ones that have taken place now.
"We thought it would be useful to meet with them and explain our point of view, and figured they would want to explain their point of view," the official told CNN. "We thought talking directly would clear up any misunderstandings about the United States."
The official said that at the meeting, the American delegation explained that the U.S. wanted to see a political process in Yemen
and that everyone, the Houthis among them, should be included.
"They are certainly entitled to be part of a political solution. But you can't attack neighboring countries, arrest people and attack the legitimate government there," the official said. "There are a lot of red lines being crossed."
The official said Houthi representatives seemed "reasonable" and "seemingly amenable" to the idea of a humanitarian ceasefire, as well as joining the political process being led by the U.N. in Geneva.
The Houthis maintained they were in fact already observing the ceasefire imposed last month, the official said, but stressed that the U.S. has information that counters that claim.
The official said the U.S. delegation also discussed what are thought to be as many as three remaining Americans in Houthi custody, after U.S. citizen Casey Coombs was released and sent to Oman Monday. The Houthis agreed to keep talking about the fate of the others.
Although another meeting between the two sides has not been set, the officials said they expect to have one in the not-too-distant future.
"My guess is there will be another meeting," the official said. "We hope to have ongoing contact with them."
The official praised the role of Oman, which, in addition to setting up and hosting the meeting, helped facilitate the release of Coombs, who was detained over the past two weeks. The Omanis also acted as intermediaries between the U.S. and Houthis for several months before the secret direct talks.
A Saudi-led coalition has launched airstrikes on Houthi targets to return Yemen's leader Abed Rabbo Mansour Hadi to power after the rebels forced him to flee the capital. Saudi Arabia also accuses Iran of arming and funding the Houthis and interfering on its border, and has sought to counter what it calls Iranian aggression in the region.
The U.S. has supplied intelligence for the Saudi-led operations and has helped implement a blockade to prevent weapons from going to the Houthis.
The presence of U.S. naval forces has helped keep Iranian ships in the area away from the country, sparking fears of a conflict between Washington and Tehran as the two sides seek to negotiate a nuclear deal by the end of June.
Patterson, who was in Saudi Arabia last week, notified the Saudi government before the meeting took place, the U.S. administration officials said.
State Department spokeswoman Marie Harf told reporters Monday that Coombs was in stable condition and that the U.S. ambassador to Oman and a consular official met him at the airport in Muscat upon his arrival to provide consular assistance.
An Oman news agency reported earlier Monday that, acting on instructions from Sultan Qaboos to assist the United States, "Oman has helped the American government ... find the missing [American] citizen in Yemen."
"We are grateful to the government of Oman and personally to Sultan Qaboos for assisting with the safe passage of a U.S. citizen to Oman," Harf said.
Several of the Americans still being held are believed to be in the capital city of Saana. It is unclear where exactly they are located and whether they're in the same place.
There may be other Americans being held inside and outside the capital, according to the officials.
At least one captive is believed to be a dual U.S.-Yemeni national. Coombs and the remaining Americans are among dozens of U.S. citizens who chose to stay in Yemen or were unable to leave the country after the U.S. closed its embassy in February and evacuated its personnel.
They were detained at different times over the past two weeks, the officials said. However, the circumstances under which they were taken into custody remain unclear.
It is also unclear why they were detained. At first, the Yemenis
thought the Houthis took them to gain leverage on peace talks with the government, but that seems to have been ruled out after the rebels made no demands.
"It looks like they were just at the wrong place at the wrong time," a Yemeni official said.
There is no indication the remaining Americans have been physically harmed.