The US military has upped the ante against Iran and warned that ships entering or exiting Iranian ports “without permission” would be “subject to interception, diversion and capture”. Countering the US, China, which sources large volume of its crude oil needs from Iran, called the blockade “dangerous and irresponsible”. President Xi Jinping said the world “must not be allowed to revert to the law of the jungle”.The restrictions applied without distinction to vessels of any flag engaging with Iranian ports, oil terminals, or coastal facilities, said the US Central Command (responsible for military operations in West Asia), which imposed the blockade at 7.30 pm (Indian time) on Monday.Iran’s Interior Minister Eskandar Momeni said his country would not be affected by the US blockade as it had more than 8,000 km of land and sea borders. Momeni instructed officials in Iran’s border provinces to facilitate the import of essential goods to “neutralise the threat” of the naval blockade.The US blockade has come into effect as the Trump administration tries to pressure Tehran into accepting its terms to end the war by trying to squeeze the Iranian economy. Iran’s armed forces have called it an “illegal act” that “amounts to piracy”.The US Central Command has enforced a blockade in the Gulf of Oman and Arabian Sea east of the Strait of Hormuz. A note to mariners issued on Monday night said: “Any vessel entering or departing the blockaded area ⁠without authorisation is subject to interception, diversion and capture. The blockade will not ⁠impede neutral transit passage through the Strait ⁠of Hormuz to or from non-Iranian destinations in the Persian Gulf.”The Iranian have also threatened that their fast missile boats named ‘Red Bees of the Persian Gulf’ were warming up. “Now, they (the US) are about to find out how a swarm can pin you down real quick,” an Iran official said.Maritime watchkeeper–the United Kingdom Maritime Trade Operations (UKMTO) Centre–issued an advisory on Monday night detailing the threats posed by the US blockade. It said, “Restrictions are being enforced affecting Iranian ports and coastal areas, including locations along the Arabian Gulf, Gulf of Oman and the Arabian Sea east of the Strait of Hormuz.” The restrictions encompass the entirety of the Iranian coastline, including ports and energy infrastructure.Neutral vessels currently within Iranian ports have been granted a limited grace period to depart. Vessels operating in the Strait of Hormuz approaches, Gulf of Oman and adjacent waters have been advised to maintain heightened situational awareness, ensure maximum bridge readiness and communicate through ‘Channel-16’, the maritime channel for ship-to-ship communications.Meanwhile, the US has pumped in its naval might, with three US carrier strike groups now converging in West Asia. The USS Abraham Lincoln is positioned in the Arabian Sea, USS Gerald R Ford is in the eastern part of the Mediterranean Sea while the USS George HW Bush has entered the Mediterranean Sea from the Strait of Gibraltar.Two US amphibious ready groups, the USS Boxer and the USS Tripoli, are also in the area. Multiple US air force planes like the KC-135, KC-46 refuellers and C-17 Globemaster are at staging areas in Jordan, Qatar and Israel. Analysts see this as the largest US naval and air concentration in the Persian Gulf since the 2003 invasion of Iraq.