The Venezuelan government has denied entry at its borders to hundreds of tonnes of humanitarian aid.
Lorries containing supplies from the United States, Brazil and Colombia were turned away.
The US, which supports the Venezuelan opposition leader Juan Guaidó, says it’s offering to provide $20m (£15m) of humanitarian supplies.
But despite the recent stand-off, not all international assistance has been rejected.
The Venezuelan government has praised Russia, an ally of president Nicolás Maduro, for sending aid and said 300 tonnes of it had been transported to Venezuela.