It comes just a day after the Conservative leader defended Britain’s links to security ally Saudi Arabia as MbS’s arrival drew mass protests over Riyadh’s human rights record.
A fiery exchange in parliament between Ms May and opposition leader Jeremy Corbyn underlined tension in Britain over MbS’s trip, which was aimed at building a broader economic partnership between the two countries.
Ms May and the crown prince used talks in Downing Street on Wednesday to lay plans for a £65 billion trade and investment package, while also touching on the Yemen conflict.
A spokesperson said: “The Prime Minister raised our deep concerns at the humanitarian situation in Yemen.
“The Prime Minister and crown prince agreed on the importance of full and unfettered humanitarian and commercial access, including through the ports, and that a political solution was ultimately the only way to end the conflict and humanitarian suffering in Yemen.”
On Wednesday, he had lunch with the Queen and the Duke of York and was to have dinner with the Prince of Wales and the Duke of Cambridge as the UK rolled out the red carpet for the controversial figure.
On Friday, he will meet Defence Secretary Gavin Williamson for talks.
MbS’s visit has caused widespread controversy over Saudi Arabia’s role in the war in Yemen, and the country’s human rights record.