(AFP) - Ethiopian Prime Minister Abiy Ahmed is due to be sworn in for a new five-year term Monday, but the milestone risks being undermined by growing alarm over the war in the north.

Abiy's Prosperity Party scored a landslide win in June elections that federal officials touted as the high-water mark of democratic reforms he initiated upon taking office in 2018.

Yet by the time voters cast their ballots, tens of thousands had been killed in the conflict in the northern Tigray region and hundreds of thousands faced famine-like conditions, according to the UN, muddying the 2019 Nobel Peace Prize winner's once-glowing reputation.

Since then, fighting has spread to neighbouring Afar and Amhara regions while Tigray has fallen under what the UN describes as a de facto humanitarian blockade, spurring fears of the mass starvation that turned Ethiopia into a byword for famine in the 1980s.

It is unclear whether Abiy's swearing-in will alter the course of the war pitting government forces against the Tigray People's Liberation Front (TPLF) rebel group, which dominated national politics before Abiy took power.

Abiy's office, which blames the rebels for starting the war last November with attacks on federal army camps, has said certain conciliatory measures like declassifying the TPLF as a terrorist group can only happen after a new government is formed.

"The position has been that any change in approach to the conflict with the forces from Tigray can only occur after the formation of a new government," said William Davison, senior Ethiopia analyst for the International Crisis Group.

International partners like the US, which has threatened to impose targeted sanctions related to the conflict, "will be looking at this closely to see if there is any shift in position", Davison told AFP.

- 'Let down' -

Relations with the international community soured further last week when Ethiopia's foreign ministry announced the expulsion of seven senior UN staff, including the local heads of the UN children's agency UNICEF and its humanitarian coordination office.

The officials were given 72 hours to leave the country.

UN Secretary-General Antonio Guterres expressed "shock" over the decision and the UN has lodged a formal protest with the Ethiopian government.

Western powers feel "let down" by Abiy, a dynamic that will shape Ethiopia's foreign relations during his second term, said Cameron Hudson, senior fellow at the Atlantic Council's Africa Center.

"The West will likely now revert to a playbook it knows... apply pressure where it can, engage where it must, and keep on the lookout for better alternatives," Hudson told AFP.

Abiy was appointed after several years of anti-government protests against the ruling TPLF-led coalition and promised to break with Ethiopia's authoritarian past, in part by holding the most democratic elections the country had ever seen.

The coalition, of which Abiy was a member, had claimed staggering majorities in the two previous elections, which observers said fell far short of international standards for fairness.

This year, some opposition parties, notably in Abiy's native Oromia region, opted to boycott the polls, complaining that their candidates had been arrested and their offices vandalised.

No voting occurred in Tigray, and races for 83 other federal parliamentary seats had to be delayed because of security or logistical issues.

Last week, authorities held elections for 47 of those seats, in the Somali, Harari and Southern Nations, Nationalities and Peoples' (SNNP) regions.

Those results, which will not have significant bearing on the balance of power in parliament, are expected later this month.

© Agence France-Presse