The United States says it is preparing new sanctions against Syria and other entities supporting President Bashar al-Assad's government, a senior U.S. official said on Friday.

“We will be tightening even further with additional sanctions that drive at both Syrian entities and those who are supporting the efforts of the Syrian government to oppress its own people,” a U.S. official told reporters traveling with U.S. Secretary of State Hillary Clinton in Ghana.

In Syria Friday, activists say government forces launched a new bombardment of Aleppo, expanding their offensive against rebel-held areas in the nation's largest city.

The Britain-based Syrian Observatory for Human Rights said government troops and rebel forces were fighting in Aleppo in addition to the new round of shelling in the city, which is Syria's commercial capital.

Journalists in Aleppo say government forces recaptured some territory after many rebel fighters pulled back to the north. The rebels have vowed to keep fighting despite shortages of weapons and munitions.

Rebel field commander Malek al-Kurdi told VOA's Persian service at the Turkish-Syrian border that the rebels desperately need international help.

Britain said Friday it will give the rebels nearly $8 million for communications equipment and medical supplies. Foreign Secretary William Hague said in an article in the Times newspaper that relationships must be built now with “those who may govern Syria in the future.” He said the money will not be allocated for weapons.

Britain will also increase its contacts with the Syrian opposition. Hague says Britain will stress to the rebels that they must adhere to standards on human rights.

Meanwhile, diplomats say former Algerian foreign minister Lakhdar Brahimi could replace Kofi Annan as the new United Nations-Arab League envoy to Syria, possibly as sooon as next week. Mr. Annan resigned from the post last week, saying divisions in the U.N. Security Council have made it impossible for him to continue.