Speaking at an oil meeting in Jamaica on Monday, Oil Minister Rafael Ramirez said Venezuela's Citgo Petroleum Corporation would distribute the donated fuel.
"We're working to put those barrels in place in the shortest time possible", Ramirez said.
President Hugo Chavez has also offered to send the gasoline plus $5 million in disaster aid and a team of 200 humanitarian workers drawn from a special force of soldiers, firefighters and other specialists.
At the same time, he has sharply criticised the US government for failing to evacuate the victims before disaster struck.
Meanwhile, Citgo has set up a centre to help hurricane victims in Corpus Christi, Texas, the Venezuelan-owned company's president Felix Rodriguez said on Sunday in a phone conversation with Chavez during the president's weekly television and radio show.
Chavez - a close ally of Cuban leader Fidel Castro and a frequent critic of US President George Bush - has said many lives could have been saved if the US government had been better prepared for Katrina.
More than 1500 Cuban doctors are also ready to leave for the US to help Hurricane Katrina victims but Washington has yet to accept the offer of help from its longtime nemesis.
Cuban President Fidel Castro paraded a small army of doctors, white-coated and carrying green knapsacks of supplies, at the Havana convention centre on Sunday night, after they dutifully reported for duty from all over the island.
"Forty-eight hours have passed and we have received no response to our offer. We will wait patiently," said Castro, who increased his offer to 1586 doctors and 34 tonnes of medicine while insisting it was not politically motivated.
"We're ready. There's a disaster in the United States, medical coverage is not sufficient, but ideology stands in the way," said doctor Rafael Vera, 43. "We lament that politics takes precedence while lives are being lost."
Castro often deploys his doctors around the world and underscores inequities in the US health system, under which 40 million US citizens have inadequate medical care.
Cuba and its northern neighbour have no diplomatic relations and regularly refuse one another's help. Cuba rejected the $50,000 Washington offered in the wake of hurricanes in 2004 and this year, and Washington declined Cuba's offer of help after the 9/11 attacks.