The Obama administration Tuesday stepped up lobbying against congressional action for new sanctions on Iran, with the White House warning such a move would lead to war.

“The American people justifiably and understandably prefer a peaceful solution that prevents Iran from obtaining a nuclear weapon, and this agreement, if it’s achieved, has the potential to do that,” White House spokesman Jay Carney told reporters. “The alternative is military action.”

Earlier in the day State Department spokeswoman Jen Psaki said John Kerry would use a closed door briefing with the Senate Banking Committee Wednesday to warn that passing new sanctions would be a “mistake.”

The intensified effort to head off any new penalties against Iran come days after a meeting between Tehran and six world powers — the US, Britain, France, China, Russia and Germany — failed to produce a deal that would see eased sanctions in return for a promise to curb nuclear activity. Another meeting is scheduled for next week.

US President Barack Obama and British Prime Minister David Cameron spoke by phone Tuesday to discuss the Iran talks and affirm their support for continuing the diplomatic track.

Carney told reporters that Americans did not want a “march to war,” which is what new sanctions would bring, indicating that lawmakers could pay politically if diplomacy with Iran failed.

Fresh from the nuclear talks, Kerry will defend the administration stance during a meeting with lawmakers Wednesday, where he will face a tough crowd.

Senator Mark Kirk (R-Illinois) said Tuesday that the administration is boxing Americans into a lose-lose situation.

“The American people should not be forced to choose between military action and a bad deal that accepts a nuclear Iran,” he said according to AFP.

In recent years, Congress has been fertile ground for tough sanctions against Tehran, with the latest such bill clearing the House of Representatives by a vote of 400 to 20. Even in cases in which the administration has demonstrated reluctance, members of both parties in Congress have enthusiastically voted in an increasingly stringent sanctions regime.

Senate Foreign Relations Committee Chairman Sen. Robert Menendez (D-NJ) warned Sunday, as details of the talks filtered out of Geneva, against a situation in which “we seem to want the deal almost more than the Iranians. And you can’t want the deal more than the Iranians, especially when the Iranians are on the ropes.”

Menendez suggested that any deal should include a cessation of enrichment and an increase in the transparency of Iran’s nuclear program. He also congratulated the French negotiators for taking a tough tone toward the Arak heavy water plant — noting that “its only purpose in a country with such large oil reserves is to make nuclear fuel for nuclear weapons.”

Menendez, who has been a key supporter of previous Iran sanctions initiatives, announced during the interview on ABC’s “This Week” that the time had come for movement on Senate legislation to increase sanctions against Iran.

“I think that the possibility of moving ahead with new sanctions, including wording it in such a way that if there is a deal that is acceptable that those sanctions could cease upon such a deal, is possible,” Menendez said. “I look forward to working with my colleagues in the Senate to move forward on a package that ultimately would send a very clear message where we intend to be if the Iranians don’t strike a deal and stop their nuclear weapons program,” he added.

The Obama administration had asked, before the recent round of talks began, that the Senate delay action on sanctions to allow negotiations to take their course.

In the wake of last week’s negotiations, there is now a three-way split in terms of priorities. In addition to the pro-sanctions and anti-sanctions camps, Sen. Robert Corker (R-TN), the ranking member on Menendez’s committee has a third direction — not to focus on pushing for harsher sanctions, but on preventing the administration from giving away too much.

Asked over the weekend about sanctions, Corker was uncharacteristically noncommittal. “I don’t know,” he began, noting that “new sanctions would not kick in for several months” and emphasizing that “the administration has dialed back the rheostat since Rouhani’s election on the existing sanctions that we have. They have a lot of ability to waive and turn down and conduct these operations in lesser or stronger ways.”

Rather than offer a strong voice for the new sanctions, Corker is instead pushing an idea that he hinted at last week — legislation that would block the president from using any of those waivers that he mentioned unless Iran meets a number of key conditions — all of which are more stringent than the reported terms of the agreement proposed in Geneva.