As uncertainty continues over the Indo-US nuclear deal in view of the political crisis in India over the agreement, the US on Monday said every passing day was making it harder to get it through.

"We believe and we continue to believe that this arrangement is in the best interests of India, the United States, and the broader international community, because it will strengthen non-proliferation regimes.

"The reality, of course, is that every day that goes by is one less day on the legislative calendar for us to be able to have Congressional action take place. So it certainly gets harder every day that this is delayed," State department's deputy spokesman Tom Casey said in his briefing.

"You know the Indian government has internal political issues that it needs to work through. And, certainly, we continue to support this and we believe it's in our interest, but it certainly becomes harder to do so as the realities of the US legislative calendar move forward," he added.

"We'd like to believe that this deal and this agreement is one that can and should be supported by whoever comes into office in January of 2009. But, obviously, the next US government will have to look at this and make their own decisions on it," the senior State Department official said.