In a statement in response to questions, Senator Mitch McConnell of Kentucky, the majority leader, said he had long warned about Russia’s work to undermine American interests in the Middle East and southwest Asia and noted that he wrote an amendment last year rebuking Mr. Trump’s withdrawal of forces from Syria and Afghanistan.
“The United States needs to prioritize defense resources, maintain a sufficient regional military presence and continue to impose serious consequences on those who threaten us and our allies — like our strikes in Syria and Afghanistan against ISIS, the Taliban and Russian mercenary forces that threatened our partners,” Mr. McConnell said.
Aides for other top Republicans either declined to comment or did not respond to requests for comment on Sunday, including Representative Kevin McCarthy of California, the top House Republican; Senator Marco Rubio of Florida, the acting chairman of the Senate Intelligence Committee; and Senator Jim Risch of Idaho, the chairman of the Senate Foreign Relations Committee.
In addition to saying he was never “briefed or told” about the intelligence report — a formulation that went beyond the White House denial of any formal briefing — Mr. Trump also cast doubt on the assessment’s credibility, which statements from his subordinates had not.
Specifically, he described the intelligence report as being about “so-called attacks on our troops in Afghanistan by Russians”; the report described bounties paid to Taliban militants by Russian military intelligence officers, not direct attacks. Mr. Trump also suggested that the developments could be a “hoax” and questioned whether The Times’s sources — government officials who spoke on the condition of anonymity — existed.
Mr. Trump then pivoted to attack former Vice President Joseph R. Biden Jr., who criticized the president on Saturday for failing to punish Russia for offering bounties to the Taliban, as well as Mr. Biden’s son, Hunter, who is the target of unsubstantiated claims that he helped a Ukrainian energy firm curry favor with the Obama administration when his father was vice president.
“Nobody’s been tougher on Russia than the Trump Administration,” Mr. Trump tweeted. “With Corrupt Joe Biden & Obama, Russia had a field day, taking over important parts of Ukraine — Where’s Hunter?”