US Secretary of State Marco Rubio on Thursday, 23 July reaffirmed the Trump administration's commitment to Southeast Asia at the ASEAN Post-Ministerial Conference in Manila, announcing $2.5 billion in US government strategic investments for the region while issuing a pointed warning that Iran's posture in the Strait of Hormuz threatened global trade and freedom of navigation.

US Investment Push in Southeast Asia

Rubio framed the financial commitments as a matter of American national interest, not foreign generosity. 'This is not charity; this is not something we're doing because we're nice people... It's in our national interest,' he said. 'Our partnership with each of your countries in the region at large is in the national interest of the United States, and we will never abandon it.'

Alongside the headline figure, Rubio highlighted the recent approval of $1.5 billion in new strategic investments through the US Development Finance Corporation, directed at aviation infrastructure, energy security, and secure supply chains across the region. He also announced nearly $130 million in assistance for demining programmes in ASEAN member states, and outlined continued US support for liquefied natural gas market development, electricity grid technologies, civil nuclear energy, regional energy infrastructure, and critical mineral supply chains.

ASEAN as Washington's Indo-Pacific Anchor

Rubio described ASEAN as the United States' primary mechanism for engagement in the Indo-Pacific, pledging the partnership would remain a long-term strategic priority. 'As President Trump stated last year at the leaders meeting, the US-ASEAN, at the summit, we're with ASEAN 100 per cent,' he said. 'This is the primary mechanism by which we engage the region, and you will continue to see our commitment to it at the highest levels.'

The remarks come as Washington seeks to reinforce its Indo-Pacific strategy amid intensifying geopolitical competition, with Southeast Asia increasingly viewed as a critical theatre for supply chain diversification and strategic alignment away from overdependence on any single power.

Iran and the Strait of Hormuz Warning

A substantial portion of Rubio's address was devoted to Iran and the Strait of Hormuz, one of the world's most critical maritime chokepoints for oil shipments. He accused Tehran of claiming a right to control transit through the waterway — a right he said existed under no recognised legal framework — and warned that allowing such a precedent would have consequences far beyond the Middle East.

'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 — a remark clearly directed at the assembled Southeast Asian foreign ministers, whose own region includes contested maritime passages.

Rubio said the United States remained open to diplomacy but signalled that patience had limits. 'The United States is always committed to diplomacy. We are open-minded and always willing to engage in negotiated settlements of differences. Unfortunately, so far, even though we have reached agreements, they have not kept their commitments,' he said, echoing earlier remarks by President Donald Trump. He added: 'If they're serious, we're serious. If they're not, then we will do what is necessary to protect that, our interest and also the interests of our allies.'

The Stakes for Southeast Asia

Rubio argued that freedom of navigation was not a regional issue but a foundational principle of the global economy. 'What is at stake here is not simply the issue of what's happening in the Straits of Hormuz, it's a very fundamental principle about freedom of navigation,' he said.

The explicit linkage between the Hormuz situation and Southeast Asia's own maritime environment — where disputes over the South China Sea remain unresolved — was notable. Rubio closed with a longer-horizon commitment: 'The United States... stands with ASEAN,' he said, adding that Washington wanted to remain 'your reliable and durable partner for the next 50 years and beyond.'

The ASEAN Post-Ministerial Conference brings together the United States and the 10-member bloc to review cooperation on regional security, economic integration, and strategic issues. The meeting is among the highest-level diplomatic engagements between Washington and Southeast Asia in the current calendar year.