The United States on Friday unveiled $45 million in new aid to Syria, as Syrian grassroots activists preparing for the fall of President Bashar al-Assad appealed to world leaders for help, AFP reported.

Hosting a meeting of the Friends of Syria group, Secretary of State Hillary Clinton said Washington was unleashing new funds to meet a growing humanitarian crisis in the bloody 18-month conflict which has claimed 30,000 lives.

“Today I am announcing an additional 30 million dollars to help get food, water, blankets, critical medical services to the people suffering under the relentless assaults,” Clinton told the meeting, according to AFP.

The new funds bumped the total U.S. commitment to humanitarian funding for Syria to $130 million so far.

In addition, Clinton also announced an extra “$15 million to support Syrian civilian opposition groups, bringing our total support to the unarmed opposition to almost $45 million.”

Washington, however, has stuck by its refusal to provide arms and military support to the Syrian rebels fighting to oust Assad, fearing it will further complicate the situation on the ground, noted AFP.

Nine Syrian activists, working with local coordination committees in cities such as Homs, were attending the meeting to spell out their needs.

Clinton also denounced Iran for the role it is playing in the conflict, amid allegations it is supplying arms and support to the Assad regime.

“There is no longer any doubt that Tehran will do whatever it takes to protect its proxy and crony in Damascus,” Clinton said.

“The regime’s most important lifeline is Iran,” Clinton added, insisting “Iran will do everything it can to evade international sanctions.”

Clinton’s announcement came as armed rebels unleashed an unprecedented barrage of mortar fire against troops in Aleppo after announcing a “decisive” battle for Syria’s second city.

Shells crashed down at a steady rate on Syria’s second city of Aleppo and clashes were widespread, leaving layers of dust and smoke, according to the residents and the Syrian Observatory for Human Rights.

“The fighting is unprecedented and has not stopped since Thursday. The clashes used to be limited to one or two blocks of a district, but now the fighting is on several fronts,” the Observatory’s Rami Abdel Rahman told AFP.

Earlier Friday, Clinton told a joint meeting of G8 countries and Arab Spring nations focusing on economic ties that they wanted “to send a clear message to all those in the region… we stand with you and we will stand with you as long as it takes.”

“Extremists are clearly determined to hijack these wars and revolutions to further their agendas and ideology, so our partnership must empower those who would see their nations emerge as true democracies,” she added.

U.S. officials insist the Syrian regime is losing ground, pointing to cracks in the Assad power structure including defections, military losses, and the loss of control of many of border crossings.

One of the major concerns is the growing refugee crisis. About one million to 1.5 million people are internally displaced, with a further 300,000 having slipped into neighboring countries, according to UN estimates.

A State Department official revealed that just this week, the US Agency for International Development (USAID) managed to sneak enough medical supplies across the border and into southern Syria to treat some 27,000 people.

U.S. officials say they are also getting appeals from Syrians inside the country to help them with organizing life inside liberated areas.

They have supplied some 1,200 pieces of electrical equipment to help opposition organizations keep in contact with each other, as the Syrian regime jams all communications, and embarked on democracy training programs.

Other initiatives included helping people to repair fuel lines, or maintain infrastructure with the Syrian regime no longer providing basic services.