WASHINGTON — The U.S. will send Ukraine nearly $3 billion in military aid, in a massive new package that will for the first time include several dozen Bradley fighting vehicles, U.S. officials said Thursday, in the Biden administration’s latest step to send increasingly lethal and powerful weapons to help Ukraine beat back Russian forces.

The aid — totaling about $2.85 billion — is the largest in a series of packages of military equipment that the Pentagon has pulled from its stockpiles to send to Ukraine. It is aimed at getting as much to the Ukrainian forces as possible during the winter months, before spring sets in and an expected increase in fighting begins.

An announcement is expected Friday, said the officials, who spoke on condition of anonymity because details of the package have not been publicly announced.

The Bradley fighting vehicles are medium-armored combat vehicles that can serve as a fortified troop carrier on the battlefield. It has tracks rather than wheels, but is lighter and more agile than a tank. It can carry about 10 personnel, and is seen as a critical way to move troops safely into battle.

Also included in the aid package will be HUMVEES, Mine Resistant Ambush Protected vehicles, or MRAPs, and a large amount of missiles and other ammunition.

The aid comes on the heels of Ukrainian President Volodymyr Zelenskyy’s dramatic visit to Washington last month, when he slipped secretly out of his war-torn nation for the first time to thank America and predict that 2023 would be a “turning point” in the conflict. In urging more support for his country’s war effort, he told Congress, “Your money is not charity,” and instead is ”an investment in the global security and democracy that we handle in the most responsible way.”

Zelenskyy and other Ukrainian officials have pressed Western leaders to provide more advanced weapons, including armored vehicles and Patriot missile batteries. The $1.85 billion aid package last month included for the first time a Patriot battery, the most advanced surface-to-air missile system the West has provided to Ukraine in the war effort. It also provided an undisclosed number of Joint Direct Attack Munitions kits, to modify massive bombs by adding tail fins and precision navigation systems so they can be guided to a target.