United States Secretary of State Hillary Clinton has pledged strong support for Somalia's Transitional Federal Government (TFG), while vowing to take action against Eritrea's "unacceptable" arms shipments to the militant group, al-Shabaab.

"If al-Shabaab were to obtain a haven in Somalia which could then attract al-Qaida and other terrorist actors, it would be a threat to the United States," Clinton said at a press conference following a closed-door meeting with the TFG president, Sheikh Ahmed Sharif in Nairobi Thursday.

Al-Shabab, an Islamist militia, is attempting to seize control of Mogadishu from the more moderate TFG. Fierce fighting has forced thousands to flee the capital city. AllAfrica publishing partner Garowe Online reported that 15 were wounded yesterday as the clashes continued.

Clinton vowed support for the TFG's effort to counter al-Shabaab, adding that the U.S. would help bolster the government's efforts on the "humanitarian front" and the "security front." Though she did not specify on what these new aid measures would entail, the U.S. government supplied TFG with a arms shipment in June to help it fight off al-Shabab.

Clinton also criticized Eritrea's "interference" in Somalia, accusing the government of arming al-Shabab. "We intend to take action if they do not cease," Clinton said.

Clinton echoed recent criticism of Eritrea from Susan Rice, the U.S. ambassador to the United Nations, who last week said that the U.S. government was "deeply concerned and very frustrated" with Eritrea's meddling in Somalia.

Eritrea has consistently denied that it provides arms to al-Shabaab. Its capital, Asmara, has often served as a safe-haven and base for Somali Islamists in recent years.

The meeting between Clinton and Sharif took place at the United States Embassy in Nairobi. It was considered too dangerous for Clinton to travel to Mogadishu.