Donald Trump has paid solemn tribute to the six million Jews killed during the Holocaust, calling on the world to never forget “history’s darkest hour”.

On a visit to the Yad Vashem Holocaust memorial in Jerusalem, the president and first lady Melania Trump laid a wreath on a stone slab under which ashes from some of those killed in concentration camps are buried.

They were joined by Israeli prime minister Benjamin Netanyahu and his wife Sara, as well as daughter Ivanka Trump and son-in-law Jared Kushner, who are White House senior advisers.

Earlier, on his fourth and final day in the Middle East, his motorcade crossed through the barrier surrounding biblical Bethlehem for a meeting with Palestinian Authority President Mahmoud Abbas, where he pressed for progress on the dormant peace process.

If Israel and the Palestinians can forge an agreement, it could “begin a process of peace all throughout the Middle East”, Mr Trump said.

Mr Abbas said he was keen to “keep the door open to dialogue with our Israeli neighbours”.

He reiterated the Palestinians’ demands, including establishing a capital in East Jerusalem, insisting that “our problem is not with the Jewish religion, it’s with the occupation and settlements, and with Israel not recognising the state of Palestine”.

Mr Trump’s visit to Jerusalem has been laden with religious symbolism. He toured the Church of the Holy Sepulchre, which by Christian tradition is where Jesus was crucified and the location of his tomb.

Wearing a black skullcap, he became the first sitting president to visit the Western Wall in Jerusalem’s Old City, the most holy site at which Jews can pray.

He was joined at the wall by his family, who separated by gender to pray. The president and Mr Kushner visited one side, while the first daughter and first lady visited a portion of the site reserved for women.

Mr Trump approached alone and placed his hand on the stone.

The visit raised questions about whether the US would indicate the site is Israeli territory. Washington has never recognised Israeli sovereignty over parts of the Old City seized in the 1967 war.

The White House struggled to answer the question. Ambassador to the United Nations Nikki Haley declared the site part of Israel, while secretary of state Rex Tillerson on Monday dodged the question. Mr Trump himself never commented.