People walk past the press center for the talks between the United States and Iran in Islamabad, Pakistan, April 11, 2026. Photo: Xinhua

Chinese Foreign Ministry spokesperson Guo Jiakun said on Monday that the situation in the Strait of Hormuz is fragile and complex." We are concerned over the US's forcible interception of the vessel." Guo's remarks came after a media inquiry that US intercepted a cargo ship sailing toward Iran, which Iran vowed retaliation and called it a "piracy" act, and that Tehran said it will not participate in a second round of talks. 

"We hope that relevant parties will honor the ceasefire agreement in a responsible manner, avoid aggravating disputes and escalating tensions, and provide necessary conditions for the restoration of normal passage through the Strait," Guo said.

The US seizure of the Iranian-flagged cargo ship TOUSKA on Sunday has cast a fresh shadow over the fragile US-Iran ceasefire set to expire by Wednesday, as well as potential peace talks, with Tehran condemning the move as "armed piracy," accusing Washington of violating the truce and vowing retaliation.

A Chinese expert said both Washington and Tehran are currently testing each other's bottom lines through calibrated moves, adding that the two sides remain unwilling to abandon deterrence.

US attacked and seized an Iranian-flagged cargo ship it said had tried to evade its naval blockade near the Strait of Hormuz on Sunday, and Iran's joint military command vowed to respond, "throwing a fragile ceasefire into question days before it expires," according to the Associated Press.

US President Donald Trump later confirmed the operation on social media. In a post published Sunday US Eastern Time, he said the US Navy guided missile destroyer USS Spruance intercepted the TOUSKA in the Gulf of Oman."

The move quickly drew a sharp response from Iran. Al Jazeera quoted a statement made by Iran's Hazrat Khatam al-Anbiya military headquarters through the Tasnim News Agency, as saying: "The aggressive America, by violating the ceasefire and committing maritime piracy, attacked one of Iran's commercial ships in the waters of the Sea of Oman by firing upon it and disabling its navigation system by deploying several of its terrorist marines on the deck of the mentioned vessel."

"We warn that the Armed Forces of the Islamic Republic of Iran will soon respond to and retaliate against this armed piracy by the US military," the statement added, according to Al Jazeera.

According to Iran International, a UK-based multilingual digital news operation, Iranian forces launched drone attacks toward some US military vessels after American forces fired on an Iranian commercial ship in the Sea of Oman, citing Tasnim news agency reported. Tasnim said the drone strikes came in response to the US attack on the Iranian vessel earlier in the day.

Both the US and Iran are testing each other's red lines through limited moves, but Washington appears more intent on displaying strength before any possible talks, Ding Long, a professor at the Middle East Studies Institute of Shanghai International Studies University, told the Global Times on Monday.

"The US likely hopes to enter negotiations from a position of pressure while also showing its domestic audience that it remains tough on Iran," Ding said. 

Commenting on the uncertainty surrounding diplomacy, AP said it was not clear where Trump 's earlier announcement on new talks with Iran now stood. He had said US negotiators would head to Pakistan on Monday.

However, according to Al Jazeera on Monday, Tehran will skip new peace talks with the US as tensions rise over US ship seizure. Citing Iranian Foreign Ministry spokesman Esmaeil Baghaei as saying that an Iranian delegation will not be attending planned talks in Islamabad, saying the US has violated the ceasefire since it began.

Previously, Iran's official IRNA news agency wrote that "Iran stated that its absence from the second round of talks stems from what it called Washington's excessive demands, unrealistic expectations, constant shifts in stance, repeated contradictions, and the ongoing naval blockade, which it considers a breach of the ceasefire," according to France 24.

Iranian state media reported on Iranian President Masoud Pezeshkian's phone conversation with Pakistan's prime minister Shehbaz Sharif earlier Sunday, about increased suspicion that the US will repeat previous patterns and "betray diplomacy."

The recent tensions and the tough rhetoric between the two sides are casting a shadow on the talks, Al Jazeera reported on Monday, while the report also said the preparations are already in place in Pakistan. Islamabad is in a state of lockdown, at least in the red zone and several other areas, where the roads are closed. The outlet also said that it has been told that several US C-17 Globemaster aircraft landed in Islamabad over the past 24 hours, and that more may be en route.

Ding noted that both sides were still exchanging threats and engaging in limited probing moves, while remaining unwilling to abandon deterrence.

"However, neither side has sufficient momentum to continue escalating. Overall, the direction of the situation remains toward de-escalation," Ding said.

When asked to comment on the ceasefire which seems to be breaking down, Guo said that the current regional situation is at a critical stage of whether the conflict could end or not. Now that the window for peace has been opened, favorable conditions need to be created to end the conflict at an early date, the spokesperson said.