The UN Crime Congress is considering how best to integrate crime prevention and criminal justice into the wider UN agenda.
UN officials say it will focus on links between security, justice and the rule of law, and the attainment of a better, more equitable world.
The meeting also highlights effects of crime on sustainable development.
UN Secretary-General Ban Ki-moon points out that the trend of criminals and terrorists supporting each other is worth attention.
"We must address the growing links between organized crimes and terrorism. Like never before, criminals and terrorists are coming together and feeding off each other. They are funding terrorists through criminal networks and growing rich through the suffering of the entire population. We must take a comprehensive approach to address extremism, trafficking, money laundering, corruption and a range of related issues."
Thousands of government officials, experts and members of non-governmental organizations from over 140 countries attend the meeting.
Chinese Justice Minister Wu Aiying is calling on all parties involved to promote international coordination and cooperation.
"International cooperation should be strengthened in the aspects of extradition of criminals, judicial assistance, and recovery of illegal assets, which leaves transnational criminals, corrupt officials and terrorists nowhere to hide."
The meeting lasts from April 12 to 19.
The UN Crime Congress is held every five years.
