Britain, France, Germany and Sweden are urging United Nations members to support a "decisive effort" to regulate conventional weapons trade.
Delegates from more than 150 countries are gathering in New York Monday to begin a month-long meeting to draft a global arms trade treaty.
Ahead of the conference, British Foreign Secretary William Hague, French Foreign Minister Laurent Fabius and German Foreign Minister Guido Westerwelle published a joint statement saying illicit arms trafficking poses a "growing threat to humanity."
They say each year millions of people around the world suffer the effects of poorly regulated arms trade.
The statement, also joined by Sweden's trade minister, calls for a "strong and comprehensive framework of common international standards" to prevent legitimate arms sales from being diverted to trafficking networks.
The diplomats note their countries are some of the largest arms exporters in Europe, and say that means they have a special responsibility to ensure the weapons are not used in a way that violates humanitarian aims or international law.