Washington (CNN) -- President Barack Obama's dismissal of the top commander in Afghanistan was "extremely unfortunate" but "necessary," according to Richard Holbrooke, the U.S. special envoy to Afghanistan and Pakistan.
Holbrooke told members of the Senate Foreign Relations Committee on Wednesday that Gen. Stanley McChrystal is a "very distinguished and fine officer."
He noted some of the barbs in the Rolling Stone magazine article that led to McChrystal's downfall were aimed at him, but Holbrooke said the story "made no difference to me" personally and didn't change his positive opinion of McChrystal.
In the article, McChrystal and his top officers were quoted making disrespectful comments about civilian officials, including Holbrooke, Vice President Joe Biden, U.S. Ambassador to Afghanistan Karl Eikenberry, and National Security Adviser Jim Jones.
Holbrooke spoke of McChrystal as he answered a question about whether members of the current U.S. leadership team in Afghanistan -- Eikenberry, Holbrooke and Gen. David Petraeus, who replaced McChrystal -- were all on the same page regarding how to proceed.
"We are absolutely on the same page when it comes to the overall strategy and working together," Holbrooke said.
The issue of McChrystal's dismissal came near the end of the hearing in which Holbrooke was peppered with questions from senators on the ultimate goal in Afghanistan and how success will be measured.
"I have heard nothing -- nothing about that," said Sen. Bob Corker, R-Tennessee. "While I respect the ambassador, I've heard a lot of process, I've heard a lot about meetings, [but] I have no earthly idea what our objectives are on the civilian front."
Corker called the hearing "an incredible waste of time," saying to Holbrooke that "I have tremendous respect for you, but maybe we have the wrong witness."
Holbrooke responded that walking away from Afghanistan would be as "catastrophic" as it was when the United States stopped funding the anti-Soviet resistance there more than 20 years ago, eventually turning the country into a haven for terrorists.
The United States needs to keep putting money into Afghanistan for continued development after its military troops leave, Holbrooke said.
"When we talk about end state, we talk about a sustainable end state which involves continued American economic and development assistance, and we continue to fulfill our obligations to train the police and the military," he said.
Corker remained unsatisfied.
"I just don't hear any clarity," he said, "I haven't understood what the administration was saying in the beginning. That's not to be critical of them. I just don't understand. I still don't understand. I've met with you and your staff over at the State Department. It's just incredibly vague to me."