Washington sent on Tuesday its newly appointed envoy to the Horn of Africa, Jeffrey Feltman, to Ethiopia and Eritrea as the fighting in the Tigray region enters its sixth month, with almost five million civilians in need.

Mr Feltman, who was appointed last week as America’s first envoy to the region, is set to arrive in Egypt on Tuesday and will conduct shuttle diplomacy between Eritrea, Ethiopia and Sudan until May 13.

“Envoy Feltman will hold meetings with officials from the respective governments as well as the United Nations and the African Union,” the State Department said.

The goal of the trip is to lead a “sustained diplomatic effort to address the interlinked political, security and humanitarian crises in the Horn of Africa,” a statement from the department read.

Of particular urgency to Washington is the unfolding crisis in Tigray. Tuesday marks six months since Ethiopian, Eritrean and allied militias began a regional offensive against the Tigray People’s Liberation Front (TPLF). The fighting has already displaced about one million civilians and has left 4.5 million in need, according to the UN.

On Tuesday, the humanitarian organisation Oxfam said the conflict, now compounded by a locust swarm, is pushing over 5 million people into “extreme levels of hunger”.

“Six months since the conflict erupted in Tigray, thousands of farmers have nothing to plant ahead of the rainy season as the crisis, compounded by climate-fuelled locust [swarms], devastated their tools,” Oxfam said.

Mr Feltman said that a worsening crisis in Tigray could destabilise the entire region in a magnitude similar to that of the Syrian war.

“Look at what the collapse of Syria and the chaos of civil war has meant … Ethiopia has 110 million people,” Mr Feltman said in an interview with Foreign Policy last week.

If the tension in Ethiopia morphs into widespread civil conflict that goes beyond Tigray, “Syria will look like child’s play by comparison,” he said.

The US has repeatedly called on Eritrea to withdraw its troops from Tigray and Mr Feltman is expected to deliver that message in person to Asmara.

Eritrea’s President Isaias Afwerki arrived in Sudan on Tuesday before Mr Feltman’s arrival.

Ethiopian and Eritrean forces have been accused of carrying out massacres, extrajudicial killings, rape and torture by Doctors Without Borders and Amnesty International.

The US has been mulling imposing sanctions on Ethiopia and Eritrea if a ceasefire is not enacted in Tigray and Asmara’s forces do not withdraw.

Another item on Mr Feltman’s agenda is the rising tension between Egypt, Sudan and Ethiopia over the Grand Ethiopian Renaissance Dam, which Cairo has called an “existential threat” to its Nile water supply.

Egypt and Sudan have warned Ethiopia against filling the reservoir without a legal agreement, something that Addis Ababa has ignored, fuelling a bigger rift with its neighbours.