The White House said Tuesday US President Barack Obama and Congress have a responsibility to "fully test" whether a "comprehensive solution" can be achieved with Iran through diplomatic means "before pursuing alternatives." White House spokesman Jay Carney told reporters "passing any new sanctions right now will undermine our efforts to achieve a peaceful resolution to this issue by giving the Iranians an excuse to push the terms of the agreement on their side." He added that "new sanctions are unnecessary right now because our core sanctions architecture remains in place, and the Iranians continue to be under extraordinary pressure. "There is no doubt in Iran that should this agreement fail, Congress and this administration will quickly impose harsh new sanctions," he affirmed. "It would make more sense to keep our powder dry until we see whether Iran violates the understanding we have reached and accordingly at that time," he remarked. Carney reiterated that "if we pass sanctions now, even with the deferred trigger the Iranians and likely, our international partners, will see us as having negotiated in bad faith, and this would have a bearing, rather, on our core sanctions architecture. "The preliminary agreement reached with the P-5 plus one is a step along the road of the process of testing whether they will change their behavior, so we think it's important to continue that process and to hold in advance any new sanctions for the time when they might be necessary and more effective," Carney stressed