Rubio spoke at the start of an annual meeting in the Philippine capital, Manila, with counterparts from the Association of Southeast Asian Nations who have expressed alarm over the resurgent war in the Middle East that has battered their region.
Despite Washington's preoccupation with the war in the Middle East, Rubio reassured "we're with ASEAN 100 per cent".
"If we create a precedent in the Middle East where a nation state can decide that they are going to control an international waterway, charge a toll and if you don't pay them, blow up your ships, we have created a very dangerous precedent which will repeat itself in other parts of the world, including in this region," he said on Wednesday.
Rubio also met the other ministers of the four-nation Quad partnership - made up of the US, Australia, India and Japan - where they discussed shared priorities around technology, humanitarian assistance, emergency response as well as maritime and transnational security.
They issued a joint statement reaffirming their commitment to their maritime security initiatives that seek to counter China's growing influence in the region.
"We are united in our conviction that peace and stability in the Indo-Pacific maritime domain underpin the security and prosperity of the region," the leaders said in a statement.
Rubio added in a post on X that "the Quad remains a priority, and we will meet again later this year".
The Trump administration has repeatedly criticised China's increasingly aggressive actions in the South China Sea to the disadvantage of smaller claimant countries such as the Philippines, Washington's oldest treaty ally in Asia.
The territorial disputes, which also involve Taiwan and ASEAN members Vietnam, Malaysia and Brunei, are high on the agenda of three days of talks that started Tuesday in Manila.
Rubio later met with his Indian counterpart, External Affairs Minister Subrahmanyam Jaishankar, where they discussed both regional issues and the Iran war, according to a US State Department spokesperson, along with a yet-to-be completed trade agreement to lower US President Donald Trump's tariffs on Indian goods.
"The secretary and Minister Jaishankar agreed on the importance of finalising the interim trade deal, which is almost complete," spokesman Tommy Pigott said.
Rubio was scheduled to meet separately with Chinese Foreign Minister Wang Yi on the sidelines of the meetings in a tightly secured convention complex by Manila Bay.
