Addressing the East Asia Summit here, Modi said that India supports the EAS declaration on the Islamic State terrorist group, according to tweets posted by external affairs ministry spokesperson Syed Akbaruddin.
The rise of jihadist group Islamic State, which indulges in brutal killings and has declared a caliphate in areas overrun by it in Syria and Iraq, is a major cause of concern in the world.
Modi said that the challenges of terrorism and extremism have increased and nations "have to ensure that cyber and space remain a source of connectivity and prosperity, not new theatres for conflict".
In reference to the territorial conflicts in the South China Sea, he said that "following international law and norms is important for peace and stability in South China Sea as well".
"In a world of inter-dependence and globalization, there is no option but to follow international laws and norms," he stressed.
Referring to the Ebola virus outbreak in West Africa, he said it has highlighted the importance of international cooperation in combating pandemics.
Modi informed the gathering that India has contributed $12 million in the efforts against Ebola.
On India's outreach to Southeast Asian countries, Modi said his government has moved with "a great sense of priority and speed" to turn the 'Look East Policy' into 'Act East Policy'."
"No other forum is so critical for peace, stability and prosperity in Asia-Pacific and the world," he said, referring to the East Asia Summit.
He suggested that countries could "start major initiatives on energy partnership, for example, in the area of solar energy".
Modi said the success of the Association of Southeast Asian Nations (ASEAN) is an "inspiration for broader integration in the Asia-Pacific region".
He said a "balanced Regional Comprehensive Economic Partnership (RCEP) agreement which gives equal emphasis to goods and services, could be a springboard for regional integration and prosperity".
The RCEP trade agreement is being negotiated by the EAS countries.
Modi also said that 251 Indian police personnel, including 104 women, remain on duty in Liberia as part of the UN Mission in Liberia, according to tweets posted by @MEAIndia.