FIRST ON FOX: GOP lawmakers sent a letter to national security adviser Jake Sullivan Monday urging him to provide more precise numbers regarding aid to Ukraine.

Sen. JD Vance, R-Ohio, along with Reps. Chip Roy, R-Texas, and Matt Gaetz, R-Fla., said the letter – first obtained by Fox News Digital – comes following a White House briefing last week when Sullivan stated that the Biden administration had sent around $79.9 billion in aid to Ukraine since the war started in February 2022.

However, a week earlier, the White House Office of Management and Budget gave Vance’s office a chart showing at least $101 billion spent, with plans for additional spending.

The group of lawmakers – who have been vocal critics of aid to Ukraine – want the $31.1 billion discrepancy between his statement and OMB’s data cleared up.

‘We write to provide you the opportunity to clarify your remarks and communicate clearly the total budgetary resources across all government departments provided for the war in Ukraine and ‘in countries impacted by the situation in Ukraine,’ as well as any other expenditures made by the U.S. taxpayer in connection to the conflict,’ they wrote.

The letter also seeks clarification on funding sources, possible reprogrammings from base funds that increased the overall expenditure, and the inclusion of additional funds found in the Pentagon’s coffers.

Lawmakers also cited a news report which found that if the government shuts down, funding for weapon shipments to Ukraine from the Department of Defense’s stockpiles would continue, with $6.2 billion in aid available. This amount, not included in the OMB spreadsheet, further complicates the total figure of assistance provided, they said.

‘The administration stated on August 10 that ‘[p]revious supplemental appropriations for direct military aid, economic and humanitarian assistance, and other support have been committed or nearly committed,’ yet somehow there are more funds available for the war in Ukraine,’ the letter stated.

In May, the Pentagon overvalued the amount of ammunition, missiles and other military equipment it sent to Ukraine by an estimated $3 billion. Since then, a chorus of mostly GOP lawmakers have called for oversight on funds sent to the eastern European country.

Fox News Digital has reached out to Sullivan for comment.