- On January 20, Iran will start eliminating higher levels of enriched uranium
- Kerry: "Iran's nuclear program will not be able to advance" for first time in 10 years
- Obama vows to veto any laws enacting new sanctions during negotiations with Iran
(CNN) -- Save the date: Iran has pledged to start eliminating some of its uranium stockpile on January 20, the White House said Sunday.
That gives an official start date for the six-month interim deal with Iran, which was first announced in November.
"As of that day, for the first time in almost a decade, Iran's nuclear program will not be able to advance, and parts of it will be rolled back, while we start negotiating a comprehensive agreement to address the international community's concerns about Iran's program," U.S. Secretary of State John Kerry said in a statement Sunday.
As part of the agreement, Iran has agreed to start eliminating its stockpile of higher levels of enriched uranium, to dismantle some infrastructure that makes higher-level uranium enrichment possible, and not to start up additional centrifuges.
In exchange, some sanctions against Iran will be eased as part of "modest relief," the White House said.
"The $4.2 billion in restricted Iranian assets that Iran will gain access to as part of the agreement will be released in regular installments throughout the six months," Kerry said. "The final installment will not be available to Iran until the very last day."
But there's a bipartisan push in Congress to tighten, rather than ease, sanctions on Iran. U.S. President Barack Obama made it clear Sunday that he was pushing back.
"Imposing additional sanctions now will only risk derailing our efforts to resolve this issue peacefully, and I will veto any legislation enacting new sanctions during the negotiation," Obama said in a written statement.
CNN's Kevin Liptak and Jamie Crawford contributed to this report.
