The United Nations envoy for Yemen arrived in Sanaa on Monday for another round of talks aimed at finding a solution to fighting in the key rebel-held port city of Hodeida.
Martin Griffiths is set to meet with Yemen's Huthi rebels, who control the capital along with the Red Sea city of Hodeida, home to the country's most valuable port.
He did not make a statement upon his arrival at the Yemeni capital's international airport.
Two weeks of UN-brokered talks have not yet found a solution to the government offensive on Hodeida, backed by the United Arab Emirates and its allies in a Saudi-led regional coalition supporting President Abedrabbo Mansour Hadi.
The Hodeida offensive has raised fears of for civilians in a country already devastated by years of war between the Iran-backed Huthis and Hadi's Gulf-backed government.
The United Arab Emirates said Sunday it had halted the offensive to give a chance to UN diplomatic efforts.
Hodeida port is the entry port for some 70 percent of imports to Yemen, where eight million people face imminent famine.
Both the UAE and the Hadi government have held firm to their rejection of anything short of a full Huthi withdrawal.
Griffiths has said a proposal to grant the UN a major role in managing the port was being studied.
The UN envoy met with Hadi in the southern city of Aden on Wednesday and is reported to be pushing for the Huthis to cede control of Hodeida to the United Nations.
He was also in Oman on Thursday, where he met top rebel negotiator Mohammed Abdulsalam, UN radio reported.
The Huthis have controlled Hodeida and its port since 2014, when they also drove the Hadi government out of the capital and seized large swathes of northern Yemen.
That sparked a Saudi-led intervention to prop up Hadi's government, since which some 10,000 people have died.
The fight for Hodeida has claimed 429 lives, according to military and medical sources.
There are no confirmations of civilian casualties, although the UN has documented thousands of residents fleeing combat zones.
The United Nations has called Yemen the world's largest humanitarian crisis.