China has called the US naval blockade of Iranian ports 'irresponsible and dangerous'.
Beijing's foreign ministry said the move would 'undermine the already fragile ceasefire agreement' and further jeopardise the safety of ships passing through the Strait of Hormuz, a critical waterway Iran effectively closed in response to US-Israeli strikes.
The blockade came into force on Monday, a day after peace talks between the US and Iran broke down in Pakistan.
US President Donald Trump has said the measure is intended to force Iran to give up its nuclear ambitions. Analysts say the move is also designed to pressure China - the biggest buyer of Iranian oil - to encourage Tehran to open the strait.
Iran's ambassador to the UN has described the US blockade as a 'grave violation' of Tehran's sovereignty.
Up until now, Chinese vessels have been among the few managing to make their way through the strait. It is not clear whether they had to pay a toll to Iran in order to do so.
The US blockade could potentially cut off China's supply and have far-reaching consequences for its economy.
China believes that only by achieving a comprehensive ceasefire and ending the war can we fundamentally create conditions for easing the situation in the strait, said China's foreign ministry spokesman Guo Jiakun.
Guo urged all parties to abide by the ceasefire arrangements, focus on dialogue and peace talks, and restore normal traffic in the strait as soon as possible.
Meanwhile, oil prices fell back below $100 per barrel on Tuesday amid these tensions, and major points of contention between the US and Iran persist.
