FIRST ON FOX: Sen. JD Vance's office will send a letter to GOP lawmakers Thursday doubling down on the claim that the Ukraine-Israel-Taiwan foreign aid package contains an "impeachment time bomb" that would tie the hands of the next administration.

Vance's memo comes a day after former Vice President Mike Pence's policy think tank, Advancing American Freedom (AAF), sent a memo to senators dismissing Vance's claims. 

The national security supplemental text assures the delivery of $1.6 billion to finance Ukraine's military as well as just under $14 billion for Ukraine Security Assistance Initiative through Sept. 30, 2025 – the same aid mechanism that Trump temporarily paused while pushing for an investigation into Biden family foreign business dealings. 

MIKE PENCE'S THINK TANK PUSHES BACK ON JD VANCE'S 'IMPEACHMENT TIME BOMB' CLAIM IN FOREIGN AID PACKAGE

JD Vance

 Republican candidate for U.S. Senate JD Vance speaks at a campaign rally at the Dayton International Airport on November 7, 2022 in Vandalia, Ohio.  (Drew Angerer/Getty Images)

AAF claimed Wednesday that it's the president’s duty to faithfully execute the law as "written into the Constitution" — known as the Take Care clause — rejecting the argument made by the Nixon administration that the clause "empowered the President to ignore federal statutes."

Vance's office said AAF was actually supporting their point that the Ukraine supplemental would tie Trump's hands if he returns to the White House.

"Therefore, they advance the claim that a future president would have a constitutional responsibility to 'faithfully execute the law' that requires him to fund Ukraine well into his second term or face a (fake) claim of a constitutional/legal violation," Vance's office wrote in the new memo. "That is exactly the claim advanced by the Ukraine Supplemental Impeachment Time Bomb."

"Administration officials have been transparent about efforts to tie the hands of a future presidential administration, with one revealing to the Washington Post that this supplemental bill is a key component of their plan to ‘future-proof aid for Ukraine against the possibility that former president Donald Trump wins his reelection bid,’" the memo continued. "Former senior administration officials, including a former director of the Office of Management and Budget, have validated that this supplemental bill may function as a "secret set of handcuffs" and that opponents of a future president’s Ukraine policy 'will use this to try and tie his hands in the initial weeks of his presidency.'"

SENATOR PAUL ASSERTS UKRAINE AID PACKAGE WOULD 'TIE THE HANDS' OF FUTURE ADMINISTRATIONS

Mike Pence

Former Vice President Mike Pence speaks at the Republican Party Of Iowa's annual Lincoln Dinner in Des Moines, Iowa, US, on Friday, July 28, 2023.  (Rachel Mummey/Bloomberg via Getty Images)

Meanwhile, AAF noted in their memo if the president wants to cut off federal aid to Ukraine, he must get approval from Congress in a 45-day timeframe, "otherwise he must dutifully execute the law as written." 

Vance's office said that rebuttal actually "reinforces" their position "that this supplemental would tie a future president’s hands on spending in Ukraine or he would risk impeachment from Democrats on the same absurd grounds as President Trump’s first impeachment."

The Trump administration, through the Office of Management and Budget (OMB), withheld a total of about $400 million in security assistance from Ukraine in 2019. This came just before Trump asked Ukrainian President Voldomyr Zelenskyy to investigate the family of his 2020 rival, Joe Biden, and while the White House allegedly was withholding an Oval Office visit from Zelenskyy in exchange for an investigation.

These actions are what fueled the impeachment effort against Trump, in which he was ultimately acquitted. 

Vance's memo argues previous Ukraine supplemental bills lacked sunset dates extending into future administrations. The Biden administration requested specific sunset dates in the current bill to extend aid into the next presidential term, which was granted despite most Senate Republicans voting against it. 

In a statement to Fox News Digital, Marc Short, AAF board chairman said "AAF will side with the Constitution on the powers given to Congress and the Executive Branch over Senator Vance's conspiracies any day."

SEN. VANCE MEMO WARNS GOP COLLEAGUES OF ‘SYSTEMIC FAILURES’ IN US AID TO UKRAINE

Zelensky and Biden

Photo of Ukraine President Zelenskyy and President Biden  (AP/Office of the President of Ukraine)

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Several other Republican allies of Trump agreed with Vance this week.

Sen. Tommy Tuberville, R-Ala., said the provision in the bill "is gonna force him to send money and spend money for Ukraine."

"This is in the bill," Tuberville told Fox News Digital. "So, it's just another situation where the Democrats are doing something and working towards making sure that money's spent in a certain area where American taxpayers and this country don't have."

Sen. Rand Paul, R-Ky, also agreed with Vance and claimed that Democrats are "setting up" for a possible Trump presidential win.