Former Sen. Joe Lieberman told House lawmakers on Tuesday that they should oppose the new Iran nuclear deal that President Obama announced just hours earlier.

"There is much more risk for America and reward for Iran than should be in this agreement. It is not the good deal for America that we all wanted," the Connecticut Democrat said. "This is precisely the outcome that for years we in Congress fought to prevent."

Lieberman has sided with congressional Republicans and Israel by opposing the direction of the Iran talks for the last few months. His remarks at the House Foreign Affairs Committee were made shortly after Israeli Prime Minister Benjamin Netanyahu said the deal is an "historic mistake."

But Nicholas Burns, a former undersecretary of state in the George W. Bush administration, urged lawmakers to support the agreement. "I'm going to support it, because I think it's the best alternative," he said, even though it contains "very painful tradeoffs."

The hearing showed immediately that the battle lines over the Iran deal are already evident. Supporters praised the agreement, which essentially freezes Iran's nuclear program for 10 years in exchange for international legitimacy and relief from sanctions that have crippled its economy, as the best that could be reached at this point with Iran.

But opponents said the Obama administration and its international partners gave away too much to an outlaw regime, crossing even their own red lines in determination to get a deal.

"The essence of this agreement is permanent concessions in exchange for temporary benefits, and that's only if Iran doesn't cheat," said Foreign Affairs Committee Chairman Ed Royce, R-Calif.

The hearing was scheduled last week before the deal was signed in anticipation that it would be concluded by then. It's the first in what's likely to be a long series of congressional hearings over the next month or more as lawmakers scrutinize the deal.

Obama's attempts to shut Congress out of the talks provoked a bipartisan backlash which resulted in enactment in May of a law giving Congress a say in any agreement. The law gives Congress 60 days to review the agreement and decide whether to accept or reject it. Lawmakers also can allow it to take effect without acting.

During that 60-day period, Obama cannot exercise his authority under current law to waive existing U.S. sanctions enacted by Congress, though he retains full authority over any sanctions imposed by the executive branch. That limitation would become permanent only if Congress adopts a resolution of disapproval and is able to override the veto Obama promised Tuesday to wield against any attempt to impede implementation of the deal.