WASHINGTON – Some U.S. officials fear the U.S. military's new regional command in Africa is poorly defined and could usurp the State Department's role in U.S. foreign policy there, according to a congressional investigator.

John Pendleton, investigator for the Government Accountability Office, also told a House panel Tuesday that the Defense Department has made progress in establishing its Africa Command but may have drastically underestimated the costs.

The Defense Department created AFRICOM last October to consolidate operations that had been split among three other regional commands, none of which had Africa as a primary focus.

The Defense Department has said that AFRICOM is intended to have a broader focus than other regional command operations. It is intended to help bolster stability and development in Africa as well as security. Unlike America's other global combat commands, plans for AFRICOM call for a civilian deputy responsible for coordinating with other U.S. government agencies on humanitarian operations.

Those goals have provoked misgivings by African countries and some U.S. agencies that the Defense Department might be encroaching on U.S. diplomatic and aid policies.

The Defense Department “has encountered some concerns from civilian agencies, African partners, and nongovernmental organizations over what the command is and what it hopes to accomplish,” Pendleton said. “For example, State and U.S. Agency for International Development officials noted that the creation of AFRICOM could blur traditional boundaries between diplomacy, development and defense, thereby militarizing U.S. foreign policy.”

Pendleton was testifying at a hearing of a subcommittee chaired by Rep. John Tierney, D-Mass., of the House Committee on Oversight and Government Reform. Tierney said in an interview that he is concerned that the Defense Department has not clearly defined AFRICOM's role.

The Defense Department says fears about AFRICOM's role in Africa are unfounded.

“USAFRICOM will support, not shape, U.S. foreign policy on the continent,” Theresa Whelan, deputy assistant secretary of defense for African affairs, told the hearing.

Several African countries, including Libya, Nigeria and South Africa, have expressed deep reservations about the command, claiming it could signal an unwanted expansion of American military influence or turn Africa into another battleground in President Bush's worldwide campaign against terror groups.

Some U.S. officials believe those worries have been exaggerated because the Defense Department has changed its message frequently about what AFRICOM is intended to be. AFRICOM officials say the command's goals have been misunderstood and emphasize there are no plans to build new U.S. military bases in Africa.

Pendleton said the most recent budget request from the Defense Department for $390 million for 2009 may significantly underestimate the costs of establishing the command in coming years. Investigators said the United States may need to spend billions.

America's focus in Africa in recent years has been to improve security and help prepare security forces to avoid future conflicts, preventing terror groups from gaining footholds and dealing with humanitarian disasters. U.S. forces have conducted training exercises with African armies for years, and most African nations have welcomed such aid enthusiastically.