GOP presses Obama to get specific

Two top Congressional Republicans say the fiscal talks beginning Thursday with Vice President Joe BidenJoe BidenThe Hill's 12:30 Report Biden spotted at Wizards playoff game Trump’s wall jams GOP in shutdown talks MORE won't be productive unless the White House releases a detailed plan for cutting the deficit. 

Senate Majority Whip Jon Kyl (R-Ariz.) and House Majority Leader Eric CantorEric CantorTrump nominates two new DOD officials Brat: New ObamaCare repeal bill has 'significant' changes Overnight Energy: Flint lawmaker pushes EPA for new lead rule MORE (R-Va.) sent a letter to Biden on Tuesday warning that the administration needs to propose fiscal reforms if it wants Congress to approve an increase to the $14.3 trillion debt ceiling.

"For these discussions to be productive and so that we can appropriately consider the president's request to increase the statutory debt limit, we anticipate the president will submit a request outlining the amount requested to increase the debt limit, along with any policy proposals to reduce spending and reform the budget process," Kyl and Cantor wrote. 

"Any increase in the statutory debt limit must be accompanied by meaningful and immediate spending reductions and binding budgetary reforms," they wrote.

The GOP lawmakers asked the White House to present a proposal that is either already written as legislation, or sufficiently detailed so that its cost could be scored by the Congressional Budget Office (CBO).

"Such information will be necessary to have meaningful discussions regarding a legislative framework," they said.

The letter from Kyl and Cantor came two days before the first meeting of a new commission of congressional deficit negotiators convened by the administration. The talks are set to begin on Thursday at Blair House. 

The Biden group is made up of Sens. Max BaucusMax BaucusChanging of the guard at DC’s top lobby firm GOP hasn’t reached out to centrist Dem senators Five reasons why Tillerson is likely to get through MORE (D-Mont.), Daniel Inouye (D-Hawaii), Jon Kyl (R-Ariz.), House Majority Leader Eric Cantor (R-Va.) and Reps. James Clyburn (D-S.C.) and Chris Van Hollen (D-Md.).

The Obama administration has repeatedly said Congress should pass an increase to the debt ceiling as soon as possible and without any additional policy provisions. But Republicans are adamant that an increase in the borrowing limit must be paired with major budget reforms.  

The administration has been mum so far on exactly how much it wants to see the ceiling go up. The Treasury Department expects to hit the ceiling on May 16 and will run out of ways to meet all of its obligations by Aug. 2.

Kyl told The Hill Wednesday that he did not think entitlement reform would be possible in the context of the Biden talks, but if others are willing to discuss it, he is as well.

Kyl said he has cause for neither optimism nor pessimism about the talks and will keep an open mind. 

-- Erik Wasson contributed to this report.