Kansas City, Mo. ? Kansas Sen. Pat Roberts, one of more than a dozen Republican senators running for re-election next year and usually a staunch defender of President Bush’s Iraq policy, said this week his support is “not locked into concrete.”

“I don’t know the answer,” Roberts said. “I don’t know anybody that does. I know the president thinks he does. His resolve is incredible, whether or not that’s the proper course of action.”

Roberts said he doesn’t yet support measures to begin withdrawing troops. But he said, “We can’t continue to be engaged in a war which the American people do not support.”

As the clock ticks toward Election Day, voter pressure is building against any lawmaker still standing with Bush on the war.

Support among Republican senators is considered crucial to Bush’s Iraq policy. Democrats hold a narrow 51-49 majority and routinely fall shy of the 60 votes needed to cut off debate and advance most anti-war legislation.

Sen. Kit Bond, R-Mo., doesn’t face re-election next year but has expressed concerns about the lack of progress in Iraq. However, he said that his GOP colleagues should wait until September, when Gen. David Petraeus, the top U.S. commander in Iraq, is to report on whether the troop surge has led to progress.

Roberts agreed with Bond that the Senate should at least wait until hearing Petraeus before it attempts to alter Iraq strategy.

But he also spoke of “probably a foregone conclusion that whatever he proposes is not going to satisfy the critics of the war.”