Syria’s main political opposition group announced that it will boycott a conference of foreign governments in Rome next month to protest the lack of a consequential international response to the country’s escalating civil war.

Following the Syrian military's recent missile strikes in Aleppo, which were reported to have killed dozens on Friday, the Syrian National Council released a statement condemning the lack of action within the international community.

“Hundreds of civilians have been killed by Scud missile strikes,” the statement read, Al Jazeera reported. “Aleppo, the city and the civilization, is being destroyed systematically.”

"The Russian leadership especially bears moral and political responsibility for supplying the regime with weapons," it added, referring to Moscow’s ties with Syrian President Bashar al-Assad.

The U.S. State Department condemned the Aleppo attack later Saturday as"the latest demonstrations of the Syrian regime's ruthlessness and its lack of compassion for the Syrian people it claims to represent."

The SNC has demanded that foreign governments do more to prevent an escalation of the violence in Syria, and it said it would not attend the Friends of Syria conference in Rome next month, which is expected to bring together representatives from nearly 100 nations, including the U.S., to discuss a diplomatic resolution to Syria’s nearly two years of armed conflict, which the United Nations estimates has claimed some 70,000 lives.

The opposition group also declined invitations to meet with the U.S. and Russian governments to protest what it called the “shameful international position” thus far.

“The international silence on the crimes committed every day against our people amounts to participating in two years of killings," the SNC said in another statement, according to the BBC.

UN Security Council members Russia and China will not attend the Friends of Syria conference, and they have previously vetoed punitive actions against the Assad regime, though the UN General Assembly has condemned the Syrian military’s use of heavy artillery in civilian-populated urban areas.

SNC spokesman Adib Shishakly told CNN on Friday that the opposition wants the U.S. in particular to provide more assistance to Syrian civilians on the ground and demanded more international pressure against countries like Russia and Iran that continue to supply the Assad regime with weapons.

“Enough is enough,” Shishakly said. “The whole world is not doing anything.”

Mass demonstrations against the Assad regime calling for democratic reforms began in March 2011 among the “Arab Spring” wave of popular uprisings throughout North Africa and the Middle East, but it later devolved into an unbridled conflict following the Syrian government’s violent crackdown on the protesters.

Various rebel groups have formed over the course of the conflict, many consisting of both domestic and foreign Islamist militants, raising international concerns about providing material to support the armed opposition.

The SNC says on its website that its goal is to “support the Syrian people's Revolution and their struggle for freedom, dignity and democracy” through the advocacy of non-violent policies, putting it at odds with the armed rebels.