WASHINGTON — Vice President Cheney said yesterday a pivotal September report on the war in Iraq is likely to show “significant progress” — putting himself ahead of President Bush, who has refused to speculate on what the report will say.

General David Petraeus, the American commander in Iraq, and Ambassador Ryan Crocker are required to report to Congress by September 15 on progress in Iraq. Their evaluation is expected to shape the administration’s next move on the war, including decisions on how many American troops will stay in Iraq, and for how long.

“The reports I’m hearing from people whose views I respect indicate that the Petraeus plan is in fact producing results,” Mr. Cheney told CNN’s Larry King in an interview to be telecast last night. “Now, admittedly, I’ve been on one side of this argument from the beginning.”

Discussing his low public approval rating, Mr. Cheney said he just doesn’t worry about it. “If you wanted to be liked, I should never have gotten into politics in the first place,” he said. “Remember, success for a politician is 50% plus one. You don’t have to have everybody on board.”

The vice president would not comment on whether Mr. Bush should eventually pardon his friend and former chief of staff, I. Lewis “Scooter” Libby. Libby was left with a $250,000 fine and two years’ probation.

“I think having the commutation of sentence decided has been a huge relief for him, but he still has a very difficult road,” Mr. Cheney said. “He’s got — obviously he needs to find work. He’s got legal bills. He carries the burden of having been convicted. All those are not easy problems.”

On other topics, Mr. Cheney:

• Agreed with a stinging letter that Eric Edelman, undersecretary of defense for policy, sent to Senator Clinton, the Democratic presidential front-runner. Mr. Edelman wrote that Mrs. Clinton reinforced enemy propaganda by raising questions about an eventual American withdrawal from Iraq.

• Declined to criticize Iraqi lawmakers for adjourning from work until September. “It’s better than taking two months off, which was their original plan,” Mr. Cheney said. “Our Congress of course takes the month of August off to go back home, so I don’t think we can say that they shouldn’t go home at all.”

• Said he had no idea what he would do when his term ends in 2009. He said he would “probably not” work in the administration of another president.