The US State Department this week has terminated a USAID initiative that invested hundreds of millions to restore Ukraine's energy grid from Russian attacks, according to a report.

Overnight power outages have occurred in parts of Ukraine following attacks on energy infrastructure, NBC News reported, citing two USAID officials who spoke on the condition of anonymity.

"It significantly undercuts this administration's abilities to negotiate on the ceasefire, and it'd signal to Russia that we don't care about Ukraine or our past investments," a USAID official involved in the Ukraine mission was quoted as saying.

"Russia is fighting a two-pronged war in Ukraine: A military one but also an economic one," the official said. "We've provided a vast amount of support to the Ukrainian government to avoid a macroeconomic crisis."

"Russia is waging both a military and economic war in Ukraine," the official said, adding: "We've helped stabilise the energy grid and prevent economic collapse. Ending this program undermines that effort."

Ukraine grapples with near-constant strikes on its energy infrastructure, causing overnight power outages in several regions.