The multinational Aman-17 naval exercise kicked off in Karachi on Friday with 37 countries taking part in the event.
Aman-17 is the fifth such exercise which Pakistan has been holding every alternate year since 2007.
Commander of the Pakistani naval fleet Vice Admiral Arifullah Hussaini inaugurated the exercise, which includes Australia, China, Indonesia, Turkey, Sri Lanka, Britain, the US, Japan and Russia at the Karachi dockyard.
The Vice Admiral said the exercise would help work against human trafficking, narcotics smuggling, and terrorism in the region, Radio Pakistan reported.
Prime Minister Nawaz Sharif extended a warm welcome to all participants and said Pakistan, being a major stakeholder in maritime security of the Arabian Sea, was fully committed to ensuring freedom of navigation and lawful maritime order.
He pointed out that maritime security challenges in the Indian Ocean were both multidimensional and multifaceted. Threats such as maritime terrorism, drug trafficking and piracy have acquired international dimensions, he said.