The Pentagon overcounted the value of weapons and other military aid it sent to Ukraine by "at least $3 billion," Defense Department officials said Thursday.

Why it matters: The accounting error may lead to "more weapons being sent to Kyiv for its defense against Russian forces," per Reuters, which first reported the news. The news comes as Ukrainian troops prepare to launch a major counteroffensive.

• House Armed Services Committee Chair Mike Rogers (R-Ala.) and House Foreign Affairs Committee Chair Michael McCaul (R-Texas) said in a joint statement Thursday: "These funds could have been used for extra supplies and weapons for the upcoming counteroffensive, instead of rationing funds to last for the remainder of the fiscal year."

Driving the news: "During our regular oversight process of presidential drawdown packages, the Department discovered inconsistencies in equipment valuation for Ukraine," said Pentagon deputy press secretary Sabrina Singh in an emailed statement Thursday evening.

• "In some cases, 'replacement cost' rather than 'net book value' was used, therefore overestimating the value of the equipment drawn down from U.S. stocks. This over-valuation has not constrained our support to Ukraine nor impacted our ability to flow capabilities to the battlefield."

What they're saying: Rogers and McCaul said the accounting error was discovered two months ago "and only today shared with Congress," which they said was "extremely problematic, to say the least."

• Representatives for the Pentagon declined to comment on Rogers' and McCaul's statement.

What we're watching: It was not immediately clear which weapons had been mistakenly overestimated.

• Defense Department officials were still trying to determine the total over-valuation.

By the numbers: The U.S. has in total "committed more than $30.4 billion in security assistance to Ukraine since the beginning of the Biden Administration," per a Pentagon statement.