The remarks by U.S. Ambassador Matthew Tueller came a day after the spokesman for Yemen's internationally recognized government called for stepped-up international pressure on the rebels, known as Houthis, who have refused to surrender Hodeida.
Speaking in the southern city of Aden, which has been serving as the seat of Yemen's government since the rebels in 2014 seized the capital of Sanaa, Tueller asked the Houthis to stop serving the interests of those who want to further "weaken" Yemen — a veiled reference to Iran.
In March 2015, a Saudi-led coalition of mainly Arab states joined the war on the side of the Yemeni government and has been fighting the Houthis since. The conflict, mostly stalemated at this point, has spawned the worst humanitarian crisis in the world today.
The last round of peace talks in Sweden late last year offered a glimpse of hope after the warring sides agreed to withdraw their forces from Hodeida. They remained, however, divided over who will run the key port once they pull out. The U.N.-brokered deal was vague, saying a "local force" would take over without specifying who would lead it.
Tueller said he is hoping "to see if the Houthis can demonstrate political maturity" and urged them to stop serving Iran's agenda and instead "start to serve the interest of the Yemeni people."
The U.S. provides billions of dollars of arms to the Saudi-led coalition and rights groups have documented the killings of thousands of civilians in coalition airstrikes. U.S. military advisers are also helping coalition commanders in intelligence gathering.
Tueller ruled out the possibility of moving the U.S. Embassy to Aden, saying it would give the impression that Washington could back a divided Yemen.
"Our hope is that we will reopen the embassy in Sanaa, the capital," he said.
On Wednesday, Rageh Badi, the Yemeni government spokesman, denounced remarks by senior rebel leader Mohammed Ali al-Houthi who earlier this week told The Associated Press that a rebel withdrawal from Hodeida would be "impossible."
Badi said such remarks could set off new fighting in Hodeida and violate the tentative peace agreement reached by the two sides in Sweden late last year.
The remarks are a "renunciation of the Hodeida agreement and a declaration of war," Badi said, urging the U.N. to prevent another "explosion of the situation" in Hodeida. The government fears the Houthis are using the current Hodeida cease-fire to dig in and plant land mines ahead of another round of fighting, he said.
Renewed all-out war in Hodeida would risk severing the main passage for humanitarian aid to the rest of the country, including northern Yemen, a Houthi heartland.