The State Department’s top Africa official, Assistant Secretary of State Jendaye Frazer, also called for renewed ceasefire talks to end the deadliest fighting that Somalia has seen in years.

US Secretary of State Condoleezza Rice was due to discuss the situation today with her visiting Ethiopian counterpart, Seyoum Mesfin, officials said.

The fighting in Mogadishu pits heavily armed Ethiopian troops allied to the country’s UN-recognised interim government against an Islamist militia known as al-Shabab and other insurgents supported by the city’s dominant Hawiye clan.

Ethiopia intervened in Somalia, with tacit US support, in December to help oust an Islamist movement which had seized control of much of the country from the transitional federal government.

Since then, Ethiopian forces and the insurgents in Mogadishu have battled with tanks, mortars and other heavy weapons in fighting that has claimed more than a thousand lives, more than 250 of them in the past week, and forced hundreds of thousands of people to flee their homes.

Ms Frazer, who visited Somalia early this month, singled out Eritrea today for helping fuel the fighting in order to weaken Ethiopia, its regional arch rival.

“Eritrea has not been playing a constructive role in Somalia because they continue to fund, arm, train and advise the insurgents, especially the al-Shabab militia,” she said.

Ms Frazer also said the Ethiopians were actively trying to negotiate a truce with the Hawiya clan, which has remained estranged from the interim government.

“We know that Ethiopia is very quietly working very closely with especially the Hawiya clan and the transitional federal government to negotiate a long-term ceasefire,” she said, without elaborating.

“We’re pushing for the ceasefire, and for those discussions to bear fruit so that they can end this violence,” she said.

Ms Frazer also called on the interim government to step up efforts to broaden its base to include more clans.

“It’s very clear that the key to solving the situation in Somalia and stabilising it is to have this inclusive dialogue,” she said.

“Trying to get the transitional federal government to reach out to the various clans and sub-clans is a large part of our diplomacy,” she said.

Ms Frazer went on to accuse the Islamist militia of trying to undermine reconciliation efforts by targeting Hawiya clan leaders willing to talk to the government.

“They are actually trying to spoil this process of political dialogue and reconciliation,” she said.

The US also backs the planned deployment of some 8000 African Union peacekeepers to help stabilise Somalia.

But so far only about 1500 Ugandan soldiers have arrived and their presence has made little difference.