Trump said countries that receive oil through the Hormuz strait should "take care of that passage", which has been effectively closed by Tehran in retaliation for the US-Israeli strikes on Iran.

He urged such countries to "just take it, protect it, use it for yourselves".

China is a major importer of oil through the vital waterway and the foreign ministry in Beijing blamed the United States and Israel on Thursday.

"The root cause of interruptions to navigation through the Strait of Hormuz is the United States and Israel's illegal military operations against Iran," ministry spokeswoman Mao Ning told a news conference.

Trump, faced with sinking approval ratings over the war, has sought to assure that the conflict is nearing an end. However, he also warned in a televised address that there would be another "two to three weeks" of heavy strikes that would "bring (Iran) back to the Stone Ages".

If no agreement with Tehran is struck, he said, Washington would eye key targets including Iran's electricity generating plants.

Asked about Trump's threats, Mao told reporters that "military means cannot fundamentally solve the problem, and the escalation of conflicts is not in the interests of either side".

China is the main buyer of Iranian oil, most of which passes through the strait.

The effective closure of the waterway has sent global oil prices surging by 40 to 50 percent, affecting key industries, particularly the aviation sector.

Several Chinese airlines, including national carrier Air China, said they will raise their fuel surcharges on domestic flights from Sunday as the war in the Middle East drives up oil prices.

Several other airlines, including Air France-KLM, Cathay Pacific, Air India, Qantas, and SAS, have raised their fares to reflect the increase in jet fuel prices, and rerouted flights to avoid the war-torn region.

A barrel of Brent oil, the benchmark reference for energy markets, has risen to around $100 since the United States and Israel attacked Iran on February 28, leading Iran to retaliate against oil installations in several Gulf states.