MANILA, Sept. 9 (Xinhua) -- The presidents of the Philippines and Singapore on Monday discussed ways to strengthen defense and security cooperation, and trade and investment flows between the two countries.

Singapore's President Halimah Yacob (L) shakes hands with Philippine President Rodrigo Duterte (R) after signing the guest book at Malacanang palace in Manila on September 9, 2019. (Photo: AFP)

"We talked about deepening our cooperation in defense and security, which includes strengthening defense dialogues and training exchanges between the military and special forces," Philippine President Rodrigo Duterte said in a speech after his meeting with visiting Singapore President Halimah Yacob.

Halimah arrived in Manila on Sunday for a five-day state visit to mark the 50th anniversary of the Singapore-Philippines diplomatic relations.

Duterte said that he and Halimah "reviewed the full range of our engagement and exchanged views on the direction of our future collaboration."

"President (Halimah) and I committed to further intensify trade and investment links, mindful of the goals we have set for ourselves under the Philippines-Singapore Action Plan," Duterte added.

Singapore is the Philippines' second highest source of investments in 2018, committing a total of 21.18 billion pesos (around 407.3 million U.S. dollars), or 11.8 percent of the Philippines' total foreign pledges.

Singapore is also the Philippines seventh largest trading partner with two-way trade at 10.49 billion U.S. dollars.

There are also more than 200,000 Filipinos living, working and studying in Singapore.

"I also sought to further our cooperation in agriculture, education and training, science and technology, tourism and cultural exchanges," Duterte said.

The two Southeast Asian leaders witnessed the signing of eight memoranda of understanding (MOUs).

"These MOUs spend many salient areas of mutual interest such as infrastructure development, sustainable urban solutions like water resource management, skills training and education cooperation in preparation for the Fourth Industrial Revolution, agri-trade, arts and culture, and data protection," Halimah said in her speech.

Halimah said the economic ties between the Philippines and Singapore "are strong and robust."

"But President Duterte and I agreed that we can do even more together. There is room to further boost trade and investment flows," she added.