Somali President Abdullahi Yusuf has called for a "speedy deployment" of peacekeepers in his war-torn country.
Islamist forces in Somalia have been routed by Ethiopian troops
He said there was a rare chance for a real political breakthrough in Somalia, plagued by violence for 15 years.
Ethiopian troops supporting the transitional government ousted Islamist forces less than a week ago.
The US has agreed to provide $10m (£5.2m) towards the funding of a proposed 8,000-strong African Union peacekeeping force.
So far, only Uganda has pledged to send troops, agreeing to provide 1,000. Nigeria, Rwanda and Tanzania are considering requests.
The $10m for the peacekeeping force is part of a total of $40m that the US government has pledged to support government efforts to restore stability in Somalia.
In Somalia itself, Ethiopian troops say they have trapped hundreds of fleeing Islamists in the southern tip of Somalia on the Kenyan border.
The US has deployed ships off the coast to hunt those trying to escape by sea.
And in another development, a top al-Qaeda leader has reportedly urged the Islamist militias to fight "crusaders".
Meanwhile, a hotel owner in Nairobi says two Somali MPs loyal to the Islamists have been arrested, although there has been no official police confirmation.
The BBC's Mohamoud Ali says another two Islamist MPs, who criticised Ethiopia's intervention at a news conference on Thursday, have also been picked up in the city.
Mr Yusuf was speaking at a high-level meeting of US, European and African envoys in the Kenyan capital, Nairobi.
He said an 8,000-strong African Union force agreed by the UN Security Council before the current hostilities should be deployed as soon as possible.
He also called for extra funds for the government and for aid work.
"Your actions would enable us to achieve objectives which not only have great significance for our people but also for the people of the sub-region as a whole," Reuters news agency quoted his speech to the diplomats as saying.
Ethiopia's Prime Minister, Meles Zenawi, has said he wants his forces out of the country in a matter of weeks.
The talks come amid fears that a protracted Iraq-style guerrilla war could be launched by the retreating Islamists, says the BBC's Karen Allen in Nairobi.
An audio message said to be from al-Qaeda's number two, Egyptian-born Ayman al-Zawahiri, called for the Islamists to use guerrilla tactics in Somalia.
"I speak to you today as the crusader invader forces of Ethiopia violate the soil of the beloved Muslim Somalia," the five-minute tape posted on a website used by militants said.
"I call upon the Muslim nation in Somalia to remain in the new battlefield that is one of the crusader battlefields that are being launched by America and its allies and the United Nations against Islam and Muslims."
EU foreign policy chief Javier Solana told the BBC that the EU was closely monitoring the situation.
SOMALIA IN NUMBERS
Ethiopia troops: 8,000-15,000
Government troops: 10,000
Islamists: 600 near Kenyan border; 3,500 around Mogadishu
Recently displaced: 30,000
Refugees in Kenya: 160,000
Sources: Somali government, UN, correspondents
"We would like to see a government as inclusive as possible and, at the same time, troops from Ethiopia will have to slowly withdraw and be substituted either by troops from the AU or eventually by troops from the UN," he said.
Assistant US Secretary of State Jendayi Frazer has indicated that the US government will be on hand to assist in any regional peacekeeping effort.
But our correspondent says the US is treading carefully. It was blamed for backing the warlords who until last June ruled for 15 violent years.
Meanwhile, Kenya's government has shut its border with Somalia, despite criticism from the United Nations' refugee agency.