The U.N. Security Council has unanimously adopted a resolution aimed at preventing terrorists from acquiring weapons of mass destruction. The measure requires all member nations to punish individuals dealing in nuclear, chemical or biological weapons technology or components.

The United States scored a diplomatic victory at the United Nations Wednesday. All 15 Security Council members voted for a U.S. drafted resolution on the proliferation of weapons of mass destruction to terrorists and other so-called non-state actors.

The measure is designed to close a loophole in weapons treaties and conventions, which apply to countries, but not to terrorist groups or black marketeers that might try to acquire such weapons.

President Bush raised the issue last September in his speech to the General Assembly.

White House spokesman Scott McClellan hailed the Security Council vote as an affirmation of the president's initiative. "This is a high priority and is important to winning the war on terrorism. And today's vote was an important step to move forward on these international efforts," he said.

Unanimous approval of the measure came after six months of sometimes contentious diplomatic wrangling among the five Security Council members.

Another member, Pakistan, dropped its objections and reluctantly went along with the majority only after last minute changes to the text.

Speaking to reporters after the vote, Pakistan's ambassador, Munir Akram, expressed strong support for President Bush's initiative. He said Pakistan's objections stemmed from concern that the resolution might give the United Nations power over national legislatures. "The concerns that arose from the resolution were with regard to the role of the Security Council, to the ability of the Security Council to legislate for other states, and the fear that the council wished to impose measures on states that they had not freely accepted," he said.

Ambassador Akram said he had also asked for and received assurances in the final draft that the resolution would not be used retroactively.

Pakistan admitted earlier this year that Abdul Qadeer Khan, revered as the father of the country's nuclear bomb, had smuggled nuclear secrets to North Korea, Iran and Libya.