"While in Oman and Saudi Arabia, Special Envoy Lenderking will meet with Yemeni, Omani, Saudi and international partners to discuss their co-ordinated efforts to further ongoing talks," a statement read.
Several milestones have been reached in Yemen where the war broke out in September 2014.
Last month, a swap involving 877 prisoners took place between the warring sides. Only days earlier, Saudi Arabia's ambassador to Yemen Mohammed Al Jaber visited the Houthi-run capital of Sanaa for talks with the Iran-backed rebels and Omani officials to discuss ending the war in Yemen and achieving political peace.
The next round of exchanging prisoners is expected to take place on May 15, Yemen's deputy minister of human rights Majid Al Fadael told The National.
"The United States is working closely with the UN, Saudi Arabia, Oman and other partners to build on the UN-mediated truce, which has delivered the longest period of calm since the war began, to support an inclusive, Yemeni-led political process that permits Yemenis to shape a brighter future for their country," the US State Department added.
Another development has taken place on the FSO Safer, a tanker carrying 1.1 million barrels of oil which was decaying in the Red Sea, giving rise to fears of a catastrophic oil spill.
The UN Development Programme in March bought its own supertanker, the Nautica, to remove the barrels on board. It is on its way to the region and is expected to make a stop in Djibouti in the coming days.
An online donor conference will be held on Thursday to fill a $29 million in funding needed to "begin the operation in the first half of this year", the UN said.