US Secretary of State Marco Rubio on 6 May sharply escalated pressure on China and Russia over the Strait of Hormuz crisis, warning that any country helping Iran evade sanctions risks facing secondary economic penalties and losing access to the US financial system. Speaking at a White House briefing, Rubio also announced that the Trump administration was preparing a renewed push at the United Nations to secure international condemnation of Tehran's actions in the Gulf.

The UN Gambit

Rubio confirmed the administration would return to the UN Security Council, acknowledging that a previous attempt had faced resistance from China and Russia. "We're going to the UN," he said. "We're going to give it another chance to be a forum in which we're not even asking people to commit troops to the region."

The secretary of state said revised language had been prepared to try to navigate a potential veto, though he was candid about the uncertainty. "We've made some slight adjustments to the language," Rubio said. "I don't know if it'll avoid a veto or not."

The US is seeking a resolution calling on Iran to halt attacks on commercial shipping, clear mines from international waters, and allow humanitarian relief through the strait. "All we're asking them to do is to condemn it, to call on Iran to stop blowing ships, to remove these mines, and to allow humanitarian relief to come through," Rubio said.

China's Economic Exposure in the Crosshairs

Rubio made an unusually direct economic argument aimed at Beijing, contending that instability in the Strait of Hormuz — through which a significant share of global energy and trade flows — ultimately damages China's own export-driven economy. "China is an export-driven economy," he said. "Well, you can't buy from them if you can't ship it there, and you can't buy from them if your economy is being destroyed by what Iran is doing."

He added: "It is in China's interest that Iran stop closing the straits. It's harming China as well." The remarks come shortly after Iran's foreign minister visited Beijing, a meeting Rubio referenced pointedly. "I hope the Chinese tell him what he needs to be told — that what you were doing in the straits is causing you to be globally isolated," he said.

Secondary Sanctions Warning

Rubio issued a broad warning to foreign financial institutions and companies assisting Tehran in bypassing US sanctions, signalling that enforcement was being actively reviewed by Treasury officials. "If you ignore our sanctions, you're going to face secondary sanctions," he said. "We're serious about our sanctions. A cost needs to be imposed on Iran for what they are doing."

When asked specifically whether Chinese banks could face penalties, Rubio declined to announce concrete measures but did not rule them out, indicating that options were on the table.

Iran's Attacks on Commercial Shipping

Rubio repeatedly condemned Iran's targeting of commercial vessels in the Strait of Hormuz, framing it as an unlawful attempt to control one of the world's most critical shipping corridors. "These guys are bombing commercial vessels," he said. "They're not bombing naval vessels; they're bombing commercial tankers."

The secretary of state described the crisis as a direct test of the United Nations' credibility. "What is the purpose of the UN?" he asked. "The UN was supposed to be a place where you could peacefully resolve global conflict."

Taiwan and the Broader US-China Picture

The briefing also touched on the wider US-China relationship ahead of an anticipated meeting between President Donald Trump and Chinese President Xi Jinping. Rubio indicated that Taiwan would likely feature in those discussions, while signalling that both sides share an interest in regional stability. "I think both countries understand that it is neither one of our interests to see anything destabilising happen in that part of the world," he said.

With the UN Security Council vote pending and secondary sanctions enforcement under active review, the coming weeks will test whether Washington's dual-track pressure — diplomatic and economic — can shift Beijing's calculus on Iran.