Citgo, Venezuela's Texas-based oil subsidiary, has suspended its scheme to provide cheap heating oil to thousands of low-income families in the US.
The programme is being halted because of falling world oil prices, the group that administers the scheme said.
The Venezuelan government says that since 2005, some 220,000 poor families in the US have benefited.
When the scheme was launched, critics said it was a publicity stunt by the Venezuelan President Hugo Chavez.
Citgo, the US refining arm of the Venezuelan state energy company PDVSA, distributed fuel to communities in 23 states, including Massachusetts, Ohio and Pennsylvania, at a 40% discount.
The scheme amounted to some $100m (£68m) of heating oil last year.
Joseph Kennedy of Citizens Energy, the charitable organisation that administers the scheme, said it had become a casualty of the fall in the global oil price.
"The current economic meltdown," he said, "has forced Citgo to re-evaluate all the assistance programnes that they provide."
Mr Kennedy, who is the nephew of the late President John F Kennedy, urged Americans who had benefited from the programme to write to President Chavez to tell him what a difference it had made to their lives.
"All of us at Citizens Energy continue to do everything we can to advocate a continuation of this vital assistance," he said in a statement.
It is probably the Venezuelan government's highest profile cutback to date as a result of the low oil price and it will provide Mr Chavez's critics with ammunition for their argument that such schemes were a misuse of the country's oil resources, says the BBC's Will Grant in Caracas.
Mr Kennedy, however, criticised US oil companies for not taking part in efforts to give heating assistance to low-income households.
"This shouldn't be the responsibility of another country. I don't get one barrel from one US company. Not one," he said.
Mr Kennedy said he had received assurances from Citgo that the programme was only being suspended and not cancelled altogether.
But no date could be given for when it might be resumed and around 20 employees from Citizens Energy have been given a leave of absence.
Source : http://news.bbc.co.uk/2/hi/7813215.stm