National security adviser Michael Flynn privately discussed U.S. sanctions against Russia with that country’s ambassador to the United States during the month before President Trump took office, contrary to public assertions by Trump officials, current and former U.S. officials said.

Flynn’s communications with Russian Ambassador Sergey Kislyak were interpreted by some senior U.S. officials as an inappropriate and potentially illegal signal to the Kremlin that it could expect a reprieve from sanctions that were being imposed by the Obama administration in late December to punish Russia for its alleged interference in the 2016 election.

Flynn on Wednesday denied that he had discussed sanctions with Kislyak. Asked in an interview whether he had ever done so, he twice said, “No.”

On Thursday, Flynn, through his spokesman, backed away from the denial. The spokesman said Flynn “indicated that while he had no recollection of discussing sanctions, he couldn’t be certain that the topic never came up.”