Saudi Arabia has proposed a ceasefire deal to end the fighting in Yemen’s six-year conflict that would include Riyadh lifting its blockade on rebel-controlled ports in the war-torn country. The initiative announced on Monday by Prince Faisal bin Farhan, the foreign minister, comes as Iran-aligned Houthi rebels have stepped up missile and drone attacks on Saudi cities and oil infrastructure. Saudi Arabia has also been under pressure from the Biden administration to end the conflict, which the UN says has triggered the world’s worst man-made humanitarian crisis.

Prince Faisal’s proposal appears to be similar to a plan backed by the US and the UN as diplomatic efforts to resolve the conflict have intensified since President Joe Biden took office. But the fighting in Yemen has escalated after the Houthis launched a fresh offensive in January to seize Marib, the only province in the impoverished country’s north outside rebel control. Saudi Arabia, which led an Arab coalition to intervene in the war in 2015 after the Houthis forced the Yemeni government into exile, has responded by bombing rebel targets in Marib and Sana’a, the capital.

Antony Blinken, US secretary of state, spoke with Prince Faisal on Monday and said they discussed working together to end the conflict, facilitating aid to Yemen and defending the kingdom from external threats. The Saudi-led coalition has long been criticised for restricting imports to Hodeida port, which is controlled by the Houthis. Riyadh claims the rebels use the port to smuggle in weapons from Iran and generate revenue through customs.

But Hodeida is a vital artery for the delivery of humanitarian aid and about 70 per cent of imports into Yemen, a country in which millions are at risk of starvation, with two-thirds of the 28m population dependent on some kind of humanitarian support.