U.S. Secretary of State Hilary Clinton will announce the measure on Thursday in Washington while meeting with Hassan Sheikh Mohamud, the Somalian president, according to Johnnie Carson, the assistant secretary of state.
"When the secretary meets with Hassan Sheikh tomorrow, she will exchange diplomatic notes with him and recognize the Somali government in Mogadishu for the first time in 20 years," Carson told a news conference on Wednesday.
“The visit here this week of the new Somalian president ... represents a significant change in the security and political situation on the ground in Somalia and our relationship with that country.”
The move may lead to comprehensive international aid to the battered Horn of Africa nation from foreign governments and agencies.
The U.S. already provides financial aid to Somalia in the form of humanitarian relief measures.
"The fact that we recognize them as a legitimate government will allow the World Bank and the [International Monetary Fund] to do things that they would not have been able to do before," a senior U.S. official told Reuters. "This is major, and it is significant."
Mohamud was elected Somali president last year in the country’s first such poll since Mohamed Siad Barre was removed from power by warlords in 1991. An intervention by the U.S. military in 1993 led to the disastrous “Black Hawk Down” episode in which two helicopters were shot down by militants, killing 18 American forces.
That marked the beginning of a harrowing slide for the East African nation, as a militant group linked to al Qaeda, Al-Shabab, took control of significant parts of the southern and central regions, leading to a lengthy counter-offensive by other African peacekeeping forces, supported by the U.S.
The ongoing conflicts have killed untold thousands of people, created hundreds of thousands of refugees, culminating finally in the formation of a new government headed by Mohamud and brokered by regional states.
"Significant progress has been made in stabilizing the country, in helping to break up and defeat Al Shabab," Carson added.
"Much more needs to be done, but we think enormous progress has been made, and we have been at the very center of this in our support for [the peacekeeping forces.]"
However, al-Shabab militants have not been completely removed from Somalian territory. On Wednesday, al-Shabab announced that they had killed a French intelligence agent named Denis Allex following a failed French raid to rescue him.