WASHINGTON — The F.B.I. director, Christopher A. Wray, defended the bureau on Tuesday amid another round of accusations that agents abused their powers in investigating the Trump campaign, saying he was unaware of any illegal surveillance and refusing to call their work “spying.”

Mr. Wray’s defense of his agency put him in direct conflict with Attorney General William P. Barr, who told lawmakers last month that he believed the F.B.I. engaged in spying on the Trump campaign.

“That’s not the term I would use,” Mr. Wray told senators during a budget hearing when asked about the attorney general’s testimony. Mr. Wray also added that he would help Mr. Barr understand the origins of the investigation into Russia’s election interference and possible ties to the Trump campaign, which the attorney general has said he is reviewing.

Mr. Barr’s politically charged description of lawful F.B.I. tactics has helped stoke claims that agents might have been acting wrongfully. Mr. Barr’s use of the “fine English word,” as he put it recently, echoes accusations made by the president and his allies. Typically, law enforcement officials do not refer to surveillance as spying.