The US has urged Ethiopia not to send its troops back into Somalia.
The senior US official for African policy Johnnie Carson told Reuters news agency such a move would be against the interests of both nations.
Ethiopia invaded Somalia in late 2006 to topple an Islamist movement in the capital Mogadishu, sparking an insurgency which is still raging.
Ethiopian troops pulled out in January but witness say their forces continue to make regular incursions.
“The Ethiopian government continues to look very closely at developments in Somalia,” said Mr Carson before a scheduled trip to Addis Ababa on Monday.
“Given the long-standing enmity between Somalis and Ethiopians, I will encourage the Ethiopians not to re-engage in Somalia,” he said.
He said such a move could prove “counterproductive” for Somalia’s fragile transitional government.
Ethiopia’s troops invaded in 2006 in support of the transitional government after Islamist rebels had declared a jihad on Ethiopia.
The US allied itself with Ethiopia and is widely reported to have provided Ethiopian forces with intelligence support during the conflict.
Since Ethiopian forces pulled out, Somalia’s long-running civil war has continued apace.
Since May more than 165,000 people have fled Mogadishu amid fighting between Islamists hardliners and government forces.
The African Union has 4,300 soldiers in Mogadishu attempting to protect the capital.