(KERO) — The U.S faces a possible setback in the effort to bring detained Americans WNBA player Brittney Griner and former marine Paul Whelan home.
The White House is now calling added details to add another prisoner to a proposed swap a "bad faith attempt by Russia to avoid the deal on the table.
The deal looks to include, Vadim Krasikov, a convicted Russian hit man in German custody.
The White House responding in a statement; "Holding two wrongfully detained Americans hostage for an assassin that's in a third country is not a serious counteroffer."
The statement came after U.S secretary of state Antony Blinken spoke with Russian foreign minister Sergei Lavrov about the possible deal.
"We had a frank and direct conversation. I pressed the Kremlin to accept the substantial proposal that we put forth," said Blinken
Sources tell ABC News that proposal is to swap Griner and Whelan for Russian arms dealer Viktor Bout who is in a U.S prison.
After the call, Blinken didn't provide many details about what the Russians said in response.
"He was very clear. He also said he is not delusional, you know, and we expect conversations and negotiations to continue," said White House Press Secretary,Karine Jean-Pierre
But Moscow says Lavrov did ask the U.S to return to quote, "Quiet diplomacy" after the White House announced an offer was on the table.
Until the deal is finalized, the family of Paul Whelan is slow to celebrate.
Whelan's brother releasing a statement to ABC News saying "I don't anticipate seeing any movement for months or at least not until Ms. Griners case has concluded."