Uganda has an advance force of 1,600 troops in Somalia
US Secretary of State Condoleezza Rice has called for more peacekeeping troops to be deployed urgently to Somalia to replace Ethiopian soldiers.
She said the US appreciated the deployment of an advance Ugandan force but they "frankly need to be joined soon by other forces".
The US is offering to help African states who send troops to Somalia.
Ms Rice is in the Ethiopian capital, Addis Ababa, for meetings on some of Africa's worst conflicts.
As well as Somalia, she is holding talks on the Democratic Republic of Congo and Sudan with regional presidents and ministers.
Ms Rice said she and Ethiopian Prime Minister Meles Zenawi had "emphasized the need for a ceasefire" between the Somali government and "non-extremist opposition groups".
She also said she had urged Mr Meles to contribute peacekeeping troops to Darfur in Sudan.
Ethiopian troops marched into Somalia a year ago to help Somalia's UN-backed interim government oust Islamist forces.
DR Congo - fighting in the east, recovering from a 1997-2002 civil war which claimed 3m lives
Somalia - thousands killed or displaced in conflict between Ethiopian-backed government and Islamist insurgents
Sudan - fragile peace between north and south, continuing conflict in Darfur
Ethiopia-Eritrea - tense peace after a 1998-2000 border war claimed 80,000 lives
The US supported the intervention which has proven unpopular, with insurgents continuing to stage attacks.
The UN says that one million Somalis have been displaced by the fighting, including 60% of the capital's residents.
Last month, Mr Meles acknowledged his troops had become bogged down, blaming divisions within the Somali government and calling for other states to send peacekeepers.
"We do believe that peace-keeping efforts need to take place in Somalia," Ms Rice said on Wednesday.
"We do believe that the Ethiopian forces should not have to stay in Somalia past a certain point but it's going to require peacekeeping forces to be fairly robust peacekeeping forces and so that will be part of my discussion."
Ms Rice was due to meet Somalia's new Prime Minister, Nur Hassan Hussein, later in Addis Ababa.
She said she would encourage him to engage the widest possible range of parties within his government.
DR Congo pledge
The US secretary of state also urged Mr Meles not to risk escalating tensions with neighbouring Eritrea.
A deadline set by an international border commission for the countries to demarcate their shared border expired on Friday without agreement.
Her first talks were on the latest fighting in DR Congo, with the presidents of Rwanda, Burundi and Uganda, as well as Congolese ministers.
They agreed to strengthen the Congolese security institutions, Ms Rice said after the talks.
All countries agreed not to "harbour negative forces" - a reference to Rwandan Hutu rebels, which are at the heart of fighting across the region.
The Congolese army, backed up by UN peacekeepers, is also trying to disarm a dissident Tutsi general.
Laurent Nkunda refuses to join the army, saying his men must keep their arms to defend themselves against the Hutus.
Rwanda denies claims it is backing Gen Nkunda.
Ms Rice also said that what she called third-party involvement might be required.
Delegates said afterwards that this could mean American and European assistance in border monitoring.
On Sudan, Ms Rice is due to discuss the tensions in the US-brokered 2005 peace deal between north and south.
"That is really an agreement that we cannot afford to let unravel," she said.
She is also expected to discuss the conflict in Darfur with African officials.
However, Sudan's government has signalled that it will not meet Ms Rice, the AP news agency reports.