WASHINGTON (AFP) - The US Treasury announced fresh sanctions on Thursday (July 21) targeting the arms and financial networks of the government of Syrian President Bashar al-Assad.

It added eight individuals and seven entities, some with links to Russia and China, to its sanctions blacklist, which aims to hamper their work by locking them out of the global financial system.

Those listed include Russia-based representatives of the Syrian firm Hesco Engineering and Construction, which the Treasury said operates energy production facilities in Syria.

The Treasury designated Yona Star International and T-Rubber for sanctions for their roles supplying the Syrian defense ministry, air force and other military bodies from their international offices. T-Rubber's China agents supplied aircraft tires to the air force, it said.

Several individuals and businesses involved in international money transfers were also cited for the blacklist.

The sanctions freeze any assets those listed might have in US jurisdictions, and ban US individuals and companies from doing business with them - including non-American banks with a US presence, which includes most major banks around the world. That could make it harder for those blacklisted to make use of international financial networks.

"The Assad regime relentlessly engages in destabilizing behavior," said Adam Szubin, Treasury Acting Under Secretary for Terrorism and Financial Intelligence in a statement.

"Treasury will continue to act against those responsible for fueling the Assad regime's repressive actions and dangerous weapons proliferation."