"We've seen this strategy before, it never works," he said.
He wants to block lifting sanctions until Iran recognizes Israel and releases U.S. hostages.
Sen. John Cornyn said that additional votes on Iran this week are "still being discussed."
The Illinois Democrat called the administration's proposal "too modest."
The GOP leader is warning Democrats not to block a resolution disapproving the deal.
The Tennessee Republican says an extension of a sanctions law would have 67 votes in the Senate.
"We have a looming government shutdown. It's right before our eyes," Reid said.
The Kentucky Republican suggested Obama and Senate Democrats were OK with "winning ugly."
Cristina Marcos 09/14/15 06:51 PM EDT
Lawmakers don't expect State of the Union-like atmosphere.
The senators also want details on the government's investigation into the server.