US Secretary of State Marco Rubio stated on Thursday that while the United States seeks an agreement with Iran to end the conflict, it will not do so "at any cost," reiterating that tolls for passage through the Strait of Hormuz are unacceptable.

"You can call it a toll, you can call it a fee, call it whatever you want—that's just wordplay," Rubio said, concluding a whirlwind tour of the Persian Gulf region in Bahrain. "That will never be an acceptable condition for any agreement."

The top US diplomat told a meeting of the six member states of the Gulf Cooperation Council (GCC) on Thursday that if Iran were to charge for transit through the Strait of Hormuz, nothing would stop all other countries worldwide near waterways from following suit, "and then there would be chaos."

Despite US officials insisting the Strait of Hormuz has reopened, the globally vital oil and gas shipping lane appeared chaotic on Thursday. A British naval authority reported receiving information that a vessel had been struck by an unidentified projectile in the strait. Hours earlier, several cargo ships had turned back while attempting to navigate the waterway.

Rubio's comments came after Iran and Oman indicated earlier this week they were working towards an agreement for the joint management of the Strait of Hormuz.

A joint statement issued by the two countries referenced the costs of managing maritime traffic. This renewed concerns that Iran might impose fees or tolls in the strategic waterway, an idea already opposed by officials from the US, Saudi Arabia, the UAE, and Qatar.

US President Donald Trump stated on Wednesday he would not accept any final deal with Iran that included service or shipping fees.

According to Rubio, Oman stated during the meeting that it does not support imposing tolls. "They signed that statement saying they will not charge any fee or toll, so I think that's good news," Rubio said, referring to a joint US-GCC statement which noted the parties "oppose any tolls, fees, or attempts to establish control over the Strait of Hormuz."

An earlier GCC statement did not explicitly mention tolls or fees but welcomed diplomatic efforts "to ensure the security of maritime passages—including the Strait of Hormuz—freedom of navigation, and adherence to the rules of international law."

Bahrain was the final stop on Rubio's three-day Gulf tour, marking his first visit to the region since the US and Iran signed an interim peace agreement. Rubio aimed to reassure regional allies that the security interests of Gulf states would be fully considered during negotiations with Iran, and that any resulting deal would be "a good agreement."

Arab Gulf states are concerned that a final agreement might fail to address issues such as Iran's ballistic missile program and its support for proxy forces in the region.