Reid said he is delaying a key vote on authorizing the use of force in Syria to let President Barack Obama publicly address the issue.
Earlier on Monday, the top Obama ally in Congress had scheduled the crucial test vote for Wednesday but then backtracked to let the US leader sell his plan on strikes against Syria.
"I'm not going to file cloture this evening on the motion to proceed to the Syria resolution," he said on the Senate floor, adding that "I don't think we need to see how fast we can do this. We have to see how well we can do this."
Amid deep divisions in Congress over the way forward, Obama met with Democrat and Republican senators on Tuesday and gave a televised address to the nation that night.
Russia, which has blocked US and British efforts to gain a United Nations resolution approving international action against Syria, appeared to open a path toward a solution on Monday when it suggested a plan for Damascus to hand over its chemical weapons.
Obama called the plan "potentially positive," and hinted at congressional delays as his administration weighs Moscow's comments.
Should there be objections to the motion, as at least one Republican senator threatened last week, the 100-member chamber would need 60 votes to move forward.
Obama's Democrats control the Senate, but it is unclear whether the president has the necessary support to meet the 60-vote threshold.
At least three lawmakers who had been among the many in the undecided column announced on Monday they would oppose the move to authorize the use of force.
"After step A, what will be steps B, C, D and E?" Veteran Republican Senator Lamar Alexander told his constituents.
"I see too much risk that the strike will do more harm than good by setting off a chain of consequences that could involve American fighting men and women in another long-term Middle East conflict."
The Senate resolution now being considered forbids US boots on the ground in Syria for combat purposes, but several war-weary lawmakers on both sides of the aisle have voiced concern that a strike would still draw the United States deeper into a Middle East military entanglement.
First-term Senate Democrat Heidi Heitkamp said she and Senator Joe Manchin, another Democrat who has voiced deep skepticism about Obama's plans, were drafting "an alternative approach" that would give Syria 45 days to sign an international chemical weapons ban and start turning over such poison gas.
Approval of Obama's plan may be tougher in the Republican-held House of Representatives, where far more lawmakers have spoken out in opposition of the strikes than in favor.
NTJ/BA