US Secretary of State Mike Pompeo said on Monday that Yemen's Houthi rebels are failing to comply with a ceasefire agreement reached during peace talks in Sweden last month.
Speaking in Riyadh on Monday, the senior diplomat said that the Iranian-backed Houthi rebels have "chosen" not to comply with the deal.
"The work that was done in Sweden on Yemen was good, but both sides [need] to honour those commitments," Mr Pompeo said following talks with Saudi King Salman and Crown Prince Mohammed bin Salman.
"Today, the Iranian-backed Houthis have chosen not to do that," he said.
Mr Pompeo was visiting Riyadh as part of a Middle East tour that aimed to convey Washington's commitment to fighting ISIS and Iran despite President Donald Trump's planned withdrawal from Syria.
Mr Pompeo who is still due to visit Oman and Kuwait will reportedly cut short his tour of the Middle East due to a family death, Reuters reported.
Mr Pompeo will still visit the Omani capital of Muscat later on Monday, but will travel to Kuwait at another time "in the future," a State Department spokesman said.
"This curtailment of travel is required so that the Pompeo family may attend a family funeral," the spokesman said.
Mr Pompeo has already made stops in Abu Dhabi, Doha, Baghdad, Amman and Cairo.
Kuwait City was the last scheduled stop on Mr Pompeo's tour, where he was due to lead the third US-Kuwaiti Strategic Dialogue, focusing on defence, cybersecurity and economic ties.
In Riyadh on Monday, he discussed attempts to find a political solution in Yemen and Syria, countering threats from Iran and holding the killers of Saudi journalist Jamal Khashoggi to account.
Mr Pompeo told the Saudi Crown Prince Mohammed bin Salman that his trip across the Middle East had been "good" so far, the Associated Press reported.
"I want to talk to you about a couple of places we've been. We think we learned a lot along the way that will be important going forward," he said.
The prince replied that the Saudis would "try to add more positivity, as much as we can".
The US Embassy in Saudi Arabia said both sides had agreed on the need for a redoubled effort for peace in Yemen.
"On Yemen, [Mr Pompeo and the Crown Prince] agreed on need for continued de-escalation and adherence to Sweden agreements, especially cease-fire and redeployment in Hudaydah. A comprehensive political solution is only way to the end the conflict," the US Embassy tweeted.
Meanwhile, Mr Pompeo sent US Undersecretary of State for Political Affairs David Hale to Lebanon on Monday to ensure the country works with the US to counter Iran's regional agenda.
Speaking from Lebanon, where he met with Prime Minister-designate Saad Hariri, Mr Hale said: “Secretary Pompeo asked me to come to Lebanon to discuss America’s regional strategy".
"We have fostered a common understanding with our allies of the need to counteract the Iranian regime’s revolutionary agenda and thwart Iran’s malign regional ambitions and activities, and that very much includes Lebanon, where only the Lebanese people, through their state, should make decisions of life and death," he added.
Mr Hale also said that the US is proceeding with efforts to counter Iran's financing of Hezbollah and the activities of the "proxy terrorist" organisation.
He said that it was unacceptable to have a militia such as Hezbollah that works — outside the control of the state — to dig "attack tunnels across the Blue Line into Israel," or assemble "an arsenal of over 100,00 missiles with which to threaten regional stability."
He also suggested that Lebanon should be cautious regarding Hezbollah's role in a new government. "The choice of government is for the Lebanese alone, but the type of government chosen concerns all of us who are interested in a stable and prosperous Lebanon," he said.
During his tour of the Middle East, Mr Pompeo announced an international summit on the Middle East in Poland, where he will seek to unite regional actors to find a solution to Iranian aggression.
National Editorial: US engagement in the Middle East is critical to global security