WASHINGTON – President Bush said Tuesday the unruly execution of Saddam Hussein “looked like it was kind of a revenge killing,” making it harder to persuade a skeptical U.S. public that Iraq’s government will keep promises central to Bush’s plan for a troop increase.

In his toughest assessment yet, Bush criticized the circumstances of Saddam’s hanging last month, as well as Monday’s execution of two top aides, including Saddam’s half brother.

“I was disappointed and felt like they fumbled them – particularly the Saddam Hussein execution,” the president said in an interview with PBS’ Jim Lehrer.

A cell phone video of Saddam’s Dec. 30 hanging showed the deposed Iraqi leader being taunted as he stood on the gallows with a noose around his neck. An official video of the execution of Saddam’s half brother showed that the hangman’s noose decapitated him. Both hangings provoked outrage around the world, but particularly among Saddam’s fellow Sunnis in Iraq.

Bush said he had expressed his displeasure about the way Saddam’s execution was handled to Iraqi Prime Minister Nouri al-Maliki. The president announced what he called a new strategy for the war last week, with much of it hinging on his trust in al-Maliki’s government to make radical changes.

“It basically says to people, ‘Look, you conducted a trial and gave Saddam justice that he didn’t give to others. But then, when it came to execute him, it looked like it was kind of a revenge killing,'” the president said.

“It makes it harder for me to make the case to the American people that this is a government that does want to unify the country and move forward,” Bush said. “And it just goes to show that this is a government that has still got some maturation to do.”

Bush agreed to the interview, to be telecast Tuesday evening on PBS’ “NewsHour With Jim Lehrer,” as well as one last weekend on CBS’ “60 Minutes” to help sell his revised war plan.

Polls show that Americans are overwhelmingly unhappy with Bush’s Iraq policy. Seventy percent oppose sending more troops to Iraq, as he intends to do, according to an Associated Press-Ipsos poll last week.

Bush said if a pollster asked for his opinion about Iraq, “I would be one of those that said, ‘No, I don’t approve of what’s taking place in Iraq.'”

He said that keeping his old policies in place in the war would lead to “a slow failure,” but withdrawing from Iraq, as some critics suggest, would result in an “expedited failure.”

“I am frustrated with the progress,” the president said. “A year ago, I felt pretty good about the situation. I felt like we were achieving our objective, which is a country that can govern, sustain, and defend itself. No question, 2006 was a lousy year for Iraq.”

Senate Democrats plan by Thursday to introduce a resolution denouncing the president’s plan, with floor debate to begin next week – around the time Bush delivers his State of the Union speech on Jan. 23.

The bill, by not eliminating funding for either current troops or the additions, would be merely an expression of Congress’ position. But it would help Democrats gauge Republican support for more aggressive legislative tactics, as well as embarrass Bush.

On Tuesday, Democrats were reaching out to potential Republican co-sponsors. Several GOP senators have spoken out against sending more troops.

Associated Press writer Anne Flaherty contributed to this report.