WASHINGTON (CNN) -- Sen. Gordon Smith, the Oregon Republican who came out against the Iraq war last month during an impassioned speech on the Senate floor, told CNN on Tuesday he thinks Sen. Edward Kennedy's bill requiring congressional approval for an increase in Iraq troops is "a good idea."

"The more the Congress can be involved in the decision making, the better -- and that is what the American people are asking for; they are going to hold us accountable then let's have the tools of accountability so we can be held responsible," Smith said.

Earlier Tuesday, Kennedy introduced a bill that requires congressional approval for an increase in troop levels and an increase in funds allocated to such a surge.

Smith also said he thinks the Iraq mission has changed from its original intent in 2002 to such a degree that a new broad congressional mandate is required.

"I personally do believe Iraq has mutated in a way that really does warrant the Congress trying to reassert itself in this," he said.

But Smith does not support withholding funds for troops already in Iraq, saying, "They are in harm's way, they are ordered to stay there, and I think it's really difficult to start shortchanging their ability to do their duty and follow the orders they are given by the executive branch."