The resolution was sponsored by the United States, with the Philippines, Spain and France (which joined at the last minute[8]) as co-sponsors. Negotiations leading up to the vote of resolution 1540 were officially open only to UN Security Council members, but information on the early drafts circulated with relative freedom and input from other states and NGOs was solicited due to the political sensitivity of the issues involved. Special attention was paid to the principal non-aligned states in order to put pressure on Pakistan, at the time a member of the Security Council, to fall in line with the majority opinion.