The top Democrat on the House Intelligence Committee was prepared on Monday to blame Donald Trump at least in part for a server breach at the Democratic National Committee, though he could not confirm who specifically was behind the attack.

In a statement that followed a briefing about the hack with intelligence officials, Rep. Adam Schiff, D-Calif., said Trump’s “admiration for Putin and his belittling of NATO” could have motivated Russia to attack the DNC, though he did not confirm the attack had in fact been traced to Moscow.