Despite weeks of tough warnings, the Obama administration has backed away from its calls to impose new and potentially crippling economic sanctions against Iran in retaliation for an alleged plot to kill Saudi Arabia's ambassador on U.S. soil, according to diplomats and American officials.

Though U.S. officials had declared that they would "hold Iran accountable" for a purported plot, they now have decided that a proposed move against Iran's central bank could disrupt international oil markets and further damage the reeling American and world economies.

The softening position illustrates how concern over the weak economy has hobbled the administration when it comes to combating what officials describe as Iran's efforts to attack U.S. interests in the Middle East and elsewhere.

U.S. officials and foreign diplomats added that the likelihood that other governments would strongly resist such a step also helped push the central bank measure from consideration and diplomatic discussion.

The pivot to more limited tactics has surprised some other governments that expected bold action after the administration warned that it would not tolerate Iranian terrorist plots on American soil. Some diplomats said it may be difficult for U.S. officials to persuade other governments to scale back their business with Iran when the United States was being so reticent.

Rather than pursue sanctions against Iran's central bank, U.S. officials now say they will seek to persuade some of Tehran's key trading partners - including the Persian Gulf states, South Korea and Japan - to join the U.S. in enforcing existing sanctions. The U.S. will also add a few more narrowly focused sanctions, they said, Los Angeles Times reported.