Singapore’s defense minister said Friday that countries need to look for practical ways to defuse incidents in the South China Sea, where China is pitted against smaller neighbors in multiple disputes over islands.

Singapore Defense Minister Ng Eng Hen told reporters on the sidelines of a meeting in Hawaii that incidents may not necessarily involve military ships. He noted navies have established protocols for when they encounter each other at sea.

Instead, confrontations may develop between fishing vessels or other civilian ships, Ng said. Defense ministers from the Association of Southeast Asian Nations (ASEAN) and U.S. Defense Secretary Ash Carter talked at their Hawaii meeting about ways to prevent such incidents from escalating, Ng said.

Singapore doesn’t have any claims to disputed islands, but Ng said it’s interested in the issue because the South China Sea is a major shipping route and many economies depend on it.

China claims virtually the entire South China Sea as its own, citing historical reasons. That has pitted it against the Philippines, Vietnam, Malaysia and Brunei, all members of ASEAN.

China has recently developed shoals and coral reefs into seven islands with massive land-reclamation work. Some of the islands have airstrips capable of handling military aircraft.

In July, an international arbitration tribunal ruled against China’s claims, saying they were illegal. Beijing has rejected the ruling and continued its activities.

Ng said the tribunal’s ruling is law, but there are “practical concerns” to consider.

“For Singapore, a non-claimant sate, our main interest is, either with or without a ruling, how do you make sure the region is still stable and to make sure you actually have mechanisms to prevent any escalations?” he said.

Carter told reporters he and his counterparts discussed improving coordination and cooperation between their militaries to keep the region’s waterways open. He said he asked the heads of the U.S. Navy and U.S. Coast Guard to hold a meeting with ASEAN partners next year to share their best practices for maritime security.

Ng said the terror threat posed by the Islamic State group was uppermost on the minds of the ministers at the meeting. “Compared to a year or even two years ago, they are more organized, they are more networked, they are more clear in their articulation of what they want to achieve,” he said.

The group has over 1,000 fighters from Southeast Asia, aims to establish an Islamic caliphate in the region and has networks to move money and weapons, he said.

But ASEAN nations would suffer in the short term if the group were defeated or diminished in Iraq and Syria because the Southeast Asian fighters there would return home, potentially re-energized and trained, he said. “It’s certainly very much a core concern,” Ng said.

The ministers recognized there was a lot they could do to address the situation by sharing information and technology, he said.