The Clinton administration on November 5 threatened to withdraw from the Anti-Ballistic Missile (ABM) Treaty if Russia keeps opposing the amendment of the pact signed in 1972 by Moscow and Washington.

"If they persist absolutely in that position, then the United States... will have to face a very difficult question, which is whether to withdraw from the treaty," said US Defense Undersecretary Walter Slocombe.

Slocombe made the remarks at the Center for Strategic and International Studies here when talking about the US plan to develop a national anti-missile defense system.

Seeking to reassure Russia, China and other critics of missile defense, the official said that such an anti-missile system would protect the United States and its allies and would not undermine global security.

President Bill Clinton would make a decision next summer at the earliest whether to order the deployment of a limited national missile defense. A bill for the move has been approved by Congress and signed by Clinton.

The US government hopes to win Russia's agreement to modify the 1972 ABM Treaty, which prohibits the kind of defensive system the Pentagon is proposing at a cost of about 11 billion US dollars.

Strongly opposing the amendment of the treaty, Moscow warned Washington that US deployment of an anti-missile defense system will result in dangerous consequences.

Slocombe stressed that the Clinton administration would prefer to preserve the ABM Treaty but will not let Russian objections stand in the way of US national security needs.

"It is not at all clear to me... that Russia would gain anything from the destruction of the arms control framework," Slocombe said. "The consequences would be difficult for Russia."

The official insisted that "the limited system we have in mind is fully compatible with the basic purpose of the ABM Treaty," which is to "ensure that each party's strategic deterrent is not threatened by the missile defenses of the other side."

"We believe that the treaty can be modified to permit the deployment of a limited national missile defense while preserving that fundamental purpose," he added.

"Indeed, the real threat to the viability of the ABM Treaty in contemporary conditions comes not from efforts to modify it to reflect current reality -- that is, the growing threat from rogue missiles; to reflect, in the treaty's own term, the strategic situation," he said.

He claimed that "the threat would come from a fixed refusal to modify it to permit the United States or, for that matter, Russia, which potentially faces the same problem, to build effective defenses against those threats."

In June, Clinton and his Russian counterpart, Boris Yeltsin, agreed to begin discussions to address both updating the ABM Treaty in light of US national missile defense plans and further reductions in strategic offensive arms, Slocombe said.

"We've judged it right to leave to President Clinton's successor and the successor of President Yeltsin the longer-term issue of follow-on negotiations on further changes to the treaty required to permit deployments to meet larger and more complex threats," he noted.

The official expressed his confidence that Russia will be finally persuaded to agree to amend the ABM Treaty.

"I believe that we can persuade them that we are serious about holding on to the structure of the ABM Treaty but that it needs to be modified to give us this protection for our own country," he affirmed.

However, he threatened to pull out of the treaty if Russia fails to agree. "If, in the end, we are unsuccessful in these negotiations, the president would have to decide whether to withdraw from the ABM Treaty under the supreme national interest clause."

"That right of withdrawal is expressly provided for in the treaty, and it always remains an option," he added. (Xinhua)