Story highlights Sen. Chuck Grassley had said he was mulling subpoenas for two senior FBI officials

A source familiar with the matter told CNN a resolution was not reached Thursday

(CNN) Deputy Attorney General Rod Rosenstein privately met Thursday with Senate Judiciary Chairman Chuck Grassley, amid a standoff where the Justice Department has prevented the committee from interviewing two senior FBI officials about the circumstances around former FBI Director James Comey's firing.

Rosenstein and Grassley sat down in Grassley's Senate office for nearly an hour. Afterward, the Iowa Republican declined to say whether they had come to an agreement.

"We've had some issues, and we discussed those issues," Grassley told CNN. "It was a very friendly meeting."

Grassley said last week he was preparing subpoenas for the two senior FBI officials the Justice Department is preventing the committee from interviewing.

Grassley and California Sen. Dianne Feinstein, the committee's top Democrat, want the FBI officials -- Carl Ghattas and James Rybicki -- to sit down for a transcribed interview to discuss the Comey firing as part of the committee's probe into any improper interference with the FBI.