The Bush administration has ordered the US military to prepare contingency plans to use nuclear weapons against at least seven countries, the Los Angeles Timeshas reported.
Citing a classified US Defence Department report, the newspaper also reported that the military was also directed to build smaller nuclear weapons for use in certain battlefield situations.
The countries named in the secret report - provided to the US Congress on January 8th - were China, Russia, Iraq, North Korea, Iran, Libya and Syria, the LA Timesreported.
The three contingencies listed for possible use of the weapons were "against targets able to withstand non-nuclear attack; in retaliation for attack with nuclear, biological or chemical weapons; or in the event of surprising military developments," according to the newspaper.
"The report says the Pentagon should be prepared to use nuclear weapons in an Arab-Israeli conflict, in a war between China and Taiwan, or in an attack from North Korea on the south. They might also become necessary in an attack by Iraq on Israel or another neighbour," the Timessaid.
"Officials have long acknowledged that they had detailed nuclear plans for an attack on Russia. However, this "Nuclear Posture Review" apparently marks the first time that an official list of potential target countries has come to light," analysts told the Times.
"This is dynamite," said Mr Joseph Cirincione, a nuclear arms expert at the Carnegie Endowment for International Peace in Washington. "I can imagine what these countries are going to be saying at the UN," he told the newspaper.
Arms control advocates told the Times"the report's directives on development of smaller nuclear weapons could signal that the Bush administration is more willing to overlook a long-standing taboo against the use of nuclear weapons except as a last resort.
However, conservative analysts said that the Pentagon must prepare for all possibilities as other countries, and some terrorist groups, are engaged in weapons development programs. Their position was that smaller weapons have a deterrent role because rogue nations or terrorists might not believe that the United States would use more destructive multi-kiloton weapons, the Timesreported.
Jack Spencer, a Defence analyst at the Heritage Foundation in Washington, told the newspaper the contents of the report did not surprise him and represent "the right way to develop a nuclear posture for a post-Cold War world."
The Pentagon refused to comment.