Washington-For the second day in a row, Republican presidential nominee Donald Trump tweeted about what he termed the “scandal” of a $400 million U.S. payment to Iran, drawing another denial from the White House.

Trump said in a tweet on Thursday that his Democratic opponent, former Secretary of State Hillary Clinton, was responsible for negotiations that led to the payment.

However, White House spokesman Josh Earnest said on Wednesday that Clinton was not behind the deal with Iran.

The accusations and counter-accusations began on Tuesday when the Wall Street Journal reported that the money was sent last January.

The newspaper said it was a form of “ransom” because it came at the time of the release of four American prisoners by Tehran.

It said a chunk of that cash was loaded on wooden pallets and secretly airlifted to Iran in an unmarked cargo plane.

In its report, the newspaper quoted U.S. and European officials, who refused to be identified.

The newspaper also said that the U.S. helped airlift the $400 million worth in foreign currencies.

Trump and the rest of the Republicans took advantage of the report and continued their campaign on the nuclear deal, which was struck more than a year ago, and said that Tehran would use the money to fund terrorism.

“If true, this report confirms our longstanding suspicion that the administration paid a ransom in exchange for Americans unjustly detained in Iran,” said House Speaker Paul Ryan.

“It would also mark another chapter in the ongoing saga of misleading the American people to sell this dangerous nuclear deal.”

“Yet again, the public deserves an explanation of the lengths this administration went to in order to accommodate the world’s leading state sponsor of terrorism.”

The White House denied the renewed accusations that it paid Iran ransom for the release of the four American prisoners.

In January, the American prisoners were released as Washington granted clemency to seven Iranians and withdrew arrest warrants for 14 others, Agence France Presse reported.

Within hours President Barack Obama announced he had also agreed to repay $1.7 billion owed to Tehran — one of a string of agreements that followed a deal to curb Iran’s nuclear program.

The White House said it was returning cash from a 1970s Iranian military order that was not fulfilled because of the Islamic Revolution.