US blocking new sanctions on Iran?

Haaretz, here

"... diplomatic sources in New York reported that American officials are working behind the scenes to prevent new sanctions from being imposed against Iran. 

U.S. officials claimed that a tough stance toward Iran could backfire, bringing about an opposite outcome to that desired by those who support such measures. 

The Obama administration, according to the diplomatic sources, has discarded the notion of direct talks with Iran. However, the United States is still interested in re-engaging Iran through the renewed discussion of its nuclear program through the five permanent United Nations Security Council members and Germany....

In addition to U.S. reluctance to enact fresh sanctions, G8 members Russia and China have been known to oppose any punitive steps against Tehran. .."