BEIRUT: New US sanctions against the Syrian government aim to "starve" the country and its neighbour Lebanon, the head of the Lebanese movement Hezbollah said Tuesday.

"The Caesar Act aims to starve Lebanon just as it aims to starve Syria," Hassan Nasrallah said in a televised speech.

"Syria has won the war... militarily, in security terms and politically," he added, describing the law which comes into force Wednesday as Washington's "last weapon" against Damascus.

The US law targets companies that deal with President Bashar al-Assad's regime, which Hezbollah, Tehran and Moscow support in Syria's conflict.

It imposes financial restrictions on the Damascus government to compel it to halt "attacks on the Syrian people", and it is expected for the first time to target Russian and Iranian entities active in Syria.

The Syrian government and loyalist businessmen are already targeted by US and European economic sanctions.

After nine years of war, Syria is mired in an economic crisis compounded by a coronavirus lockdown and a dollar liquidity crisis in Lebanon, a major conduit for regime-held regions.

A large chunk of Syria's population is living in poverty, prices have soared and the value of the Syrian pound has hit record lows against the dollar on the black market.

Nasrallah also accused the United States of engineering the collapse of the Syrian currency, but vowed that Assad's allies would stand by the regime.

"The allies of Syria, which stood by its side during the war... will not abandon Syria in the face of economic warfare and will not allow its fall, even if they are themselves going through difficult circumstances," he said.

Lebanon too is experiencing the worst financial meltdown since the end of its own 1975-1990 civil war, as well as being rocked by months of anti-government protests.

Nasrallah called on the Lebanese government "not to submit" to the Caesar Act.

The United States on Tuesday warned Assad that he would never secure a full victory and must reach a political compromise.

Kelly Craft, the US ambassador to the United Nations, urged him to accept a Security Council resolution calling for a ceasefire, elections and political transition along with UN-led talks.

"The Assad regime has a clear choice to make: pursue the political path established in Resolution 2254, or leave the United States with no other choice but to continue withholding reconstruction funding and impose sanctions against the regime and its financial backers," Craft said.