Yemeni officials say the Saudi-led coalition has not allowed ships to deliver much-needed aid.
On Monday, Saudi Arabia said it would start reopening some Yemeni sea and airports.
It tightened restrictions on the country after Houthi rebels fired a missile at Riyadh 11 days ago.
But officials at Hudaida port, the main entry point for aid, say it remains shut.
The UN is calling for a lifting of the blockade, warning that Yemen could suffer the worst famine in decades.
Al Jazeera’s Natasha Ghoneim reports.