President Rodrigo Duterte has warned there would be trouble if China unilaterally digs oil and other resources in the disputed South China Sea.

In a speech in Cebu City on Tuesday, Duterte reiterated that he told Chinese President Xi Jinping that the Philippines has also a claim in the disputed waters.

While he is not yet asserting the arbitral ruling with China, Duterte said, "if you do it alone, there will really be a trouble."

"Because if you struck oil now...the uranium there...the oil, we will have a problem there," he said, adding that China would see Interior and Local Government Secretary Eduardo Ano bringing a "bolo to hack the Chinese."

Duterte reiterated that before he steps down from office, he would raise to China the ruling of the Permanent Court of Arbitration in favor of the Philippines, invalidating China's sovereign and historic claim in almost the entire South China Sea through the nine-dash line.

The Philippines and China, along with Brunei, Malaysia, Vietnam and Taiwan, have been claiming partially or wholly the South China Sea. Celerina Monte/DMS