NAIROBI, KENYA - The U.S., France and Germany have joined other countries in urging their citizens to leave Ethiopia as fighting between federal forces and rebel groups moves closer to the capital, Addis Ababa. The U.N. has also announced evacuation flights for family members of its staff in the country. The presidents of neighboring Kenya and South Africa have joined calls for an urgent cease-fire.

As the security situation worsens in Ethiopia, there are increasing concerns about what happens next.

William Davison is the International Crisis Group's Senior Analyst for Ethiopia.

"There is a real prospect of the war coming to Addis Ababa and that could have even more terrible consequences we have seen so far we could see, very serious urban warfare. We could see Amhara-Oromo clashes if the OLA is involved lots of popular resistance obviously to the Tigray forces, the potential breakdown in government authority if there is an effort to regime change. We could see the violence against Tigrayans civilians increase and the repression rapidly. So definitely a need for a cease-fire," he said.

CNN reports the U.S. military has prepared special forces to assist its embassy workers and citizens if the security situation deteriorates in the Horn of African nation.

Briefing reporters in Washington Tuesday, U.S. Special Envoy for the Horn of Africa Jeffrey Feltman said there was progress in getting all parties to agree to a cease-fire.

Feltman expressed fears the military confrontation threatens Ethiopia's stability and unity.

An unarmed vigilante searches a vehicle at a neighborhood in Bole, following Ethiopian Prime Minister Abiy Ahmed's call for citizens to protect their areas from Tigray People's Liberation Front (TPLF), in Addis Ababa, Nov.19, 2021.

The Kenyan and South African presidents Tuesday also called for a cease-fire.

In November of last year, armed conflict broke out in the Tigray region between Ethiopian government forces and the Tigray People's Liberation Front. Since then, the conflict has spread to other parts of the country.

Tigray forces and the Oromo Liberation Army threaten to drive Ethiopia's Prime Minister Abiy Ahmed out of power by storming Addis Ababa.

On Tuesday, Abiy said he would be at the front line to guide troops against the advancing rebel groups.

Tobias Wellner is a sub-Saharan Africa senior intelligence analyst with Dragonfly Intelligence, a group that works on global security and political risks. He said Abiy's plan to lead the military on the battlefront is to keep the troops' morale high.

"It's really to rally support as the government is struggling to defend against the advancing rebel forces. I personally think it's very unlikely that Abiy is actually going to fight himself; it's more of a propaganda act and it also means it's a sign that Abiy will fight rather than step down from his position," said Wellner.

On Wednesday, Ethiopia government spokesman Legesse Tulu said the prime minister had arrived at the battlefront without giving details.

Tulu also said Abiy's deputy, Demeke Mekonnen Hassen, is handling government activities while he is away.

New military recruits who are joining the Ethiopian National Defense Force hold Ethiopian national flags during the send-off ceremony in Addis Ababa, Nov. 24, 2021.

Wellner said a victory for either the rebel groups or the government will create more rebellion in the country.

He said there will be no winner in this war.

"The connections between the TDF and OLA and other rebel groups that have joined the fray, it's a very cautious and not so strong alliance. Right now they are under the umbrella of opposing Abiy Ahmed but if they need to rule Ethiopia is a whole 'nother question, then the Ethno-politics will come out and make that alliance very shaky. Last scenario stalemate there is going to be some sort of cease-fire that will often be broken," said Wellner.

The Tigray leadership is calling on lifting the humanitarian blockade so that more than 400,000 people can receive much-needed humanitarian assistance. The government wants Tigray forces and other rebel groups to leave areas of the country they have captured.