A UN-chartered ship loaded with Ukrainian wheat destined for millions at risk of starvation in Ethiopia arrived in Djibouti on Tuesday.

The bulk carrier MV Brave Commander, which is carrying 23,000 tons of grain, docked in the Horn of Africa port city, the UN's World Food Programme  (WFP) said, two weeks after leaving a Black Sea port in Ukraine.

"We have officially docked! The first WFP ship to carry Ukrainian grain since February has just arrived in Djibouti," WFP Executive Director David Beasley said on Twitter. 

"Now, let's get this wheat offloaded and on to Ethiopia."

The UN agency said food insecurity and malnutrition are a major concern across Ethiopia, with an estimated 20.4 million people in need of food support.

Ukraine, one of the world's largest grain exporters, was forced to halt almost all deliveries after the confilict with Russia started in February, raising fears of a global food crisis.

Exports of grains and other foodstuffs and fertilizers from three Black Sea ports resumed at the start of August under a deal between Kiev and Moscow that was brokered by the UN and Turkey in July. According to figures late last week, more than 720,000 tons of grain have already left Ukraine.

The WFP said earlier that the number of people at risk of starvation in the drought-ravaged Horn of Africa region has increased to 22 million.

"There is still no end in sight to this drought crisis, so we must get the resources needed to save lives and stop people plunging into catastrophic levels of hunger and starvation," Beasley said at the time.