May's trip to Saudi Arabia was for talks with the king and Crown Prince Mohammed bin Salman over the kingdom-led war in Yemen. She's the second European leader to specifically seek out the crown prince as he amasses power.
May's visit was expected to include her asking Crown Prince Mohammed to allow humanitarian aid through Yemen's port of Hodeida, which is held by the Shiite rebels being targeted in the Saudi-led war.
A U.N.-chartered aid vessel docked at Hodeida on Tuesday.
"We are very clear that we want to see full humanitarian and commercial access through the port of Hodeida," May said Tuesday. "Obviously that is an issue I will be raising when I am in Saudi Arabia."
Saudi Arabia closed off Yemen's seaports and airports over a Nov. 4 rebel ballistic-missile launch that targeted the Saudi capital of Riyadh. The kingdom said it intercepted the missile, the deepest yet to penetrate the country.
Under intense international pressure, Saudi Arabia later promised it would reopen the ports for humanitarian aid.
The state-run Saudi Press Agency said May met with King Salman, Crown Prince Mohammed and other officials to discuss regional and bilateral issues, without elaborating.
The Saudi-led coalition began its war in Yemen in March 2015 on behalf of Yemen's internationally recognized government against the Shiite rebels known as Houthis and their allies.
The conflict has pushed the Arab world's poorest country to the brink of famine. The war has killed over 10,000 civilians, displaced 3 million people and left much of the infrastructure in ruins.
May has faced increasingly calls to stop British arms sales to Saudi Arabia amid the conflict, which has seen kingdom-led airstrikes kill hundreds of civilians. Britain has licensed over $6.1 billion worth of arms sales to Saudi Arabia since the war began.
May's visit seeking out Crown Prince Mohammed comes as the 32-year-old son of King Salman now appears to hold the levers of power in Saudi Arabia. French President Emmanuel Macron made a surprise visit to the kingdom earlier this month as well, to see the young royal.
In recent weeks, the crown prince led what the kingdom described as an anti-corruption campaign, arresting prominent princes, business leaders, military officials and others. He also was the architect of the kingdom's war in Yemen, which has been at a stalemate for months.
Earlier on Wednesday, May arrived in Baghdad to an honor guards' greeting, welcomed by Iraqi Prime Minister Haider al-Abadi.
The visit came as the Islamic State group has been driven out of the last town it held in Iraq and has lost its self-described capital in Syria in recent weeks.
"In Iraq, we are working together to defeat Daesh and my visit comes at a critical moment as we see the caliphate collapsing with the fall of Mosul and Raqqa," May told journalists, using an Arabic acronym for the extremist group.
"We want to ensure that Iraq can in the future provide that strong, stable and unified state that can provide the security, jobs and opportunities that all Iraqis want and deserve," she added.
Al-Abadi said May's visit showed Britain's "support and help" in fighting the Islamic State group. Some 600 British troops are deployed to the country.
"Iraq is about to enter a new stage of rebuilding, reconstruction and investment," al-Haider said. "Today, we discussed with the prime minister the strengthening of economic and commercial ties between the two countries."
May also visited Camp Taji, a coalition base north of Baghdad, where around 80 British troops are currently based.
May also will visit Jordan and meet with King Abdullah II on her trip.
Associated Press writer Jon Gambrell in Dubai, United Arab Emirates, contributed to this report.
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