Britain, the United States and nine other countries have agreed to plans to seek weapons of mass destruction by boarding ships, forcing suspected planes to land and inspecting cargoes.
The agreement, which came at the end of a two-day meeting in Paris yesterday, outlines steps members should take to increase co-operation on uncovering transfers of weapons, delivery systems and related materials.
Part of the US government's Proliferation Security Initiative, the statement committed members to change national and international laws to strengthen those efforts, and to share intelligence on weapons movements.
The guidelines will now be distributed to other countries.
Mr John Bolton, US under-secretary of state for arms control, said Washington was particularly interested in winning Chinese and Russian support. The two countries are not among the 11 members.
In addition to Britain and the United States, the members are Australia, France, Germany, Italy, Japan, The Netherlands, Poland, Portugal and Spain.
Mr Bolton dismissed concerns that the programme could give the United States and other countries too much power to stop ships in international waters.
He argued that there is "abundant authority" under existing law to conduct interceptions, most of which he said take place in countries' territorial waters anyway. In cases where the legal cover is not clear, he said members would attempt to strengthen the laws.