Pope Leo set off for Cameroon on Wednesday, where he is expected to appeal for peace in the simmering conflict in the country's English-speaking regions on the second leg of an ambitious 10-day tour of four African countries.

Leo, who was attacked again overnight by U.S. President Donald Trump over the pope's opposition to the Iran war, will arrive from Algeria, where he blasted violations of international law by "neocolonial" world powers.

Leo left Algiers on Wednesday morning and was expected to land in Yaounde, Cameroon's capital, around 3:20 p.m. (1420 GMT), ahead of a meeting with President Paul Biya and an address to national leaders.

Cameroon is a former German colony that was divided by Britain and France after World War One. Over the last decade, thousands have died in violence between government forces and separatist groups in its two anglophone regions.

A separatist alliance said on Monday it would observe a three-day "safe travel passage" to allow ​civilians and visitors to move freely during the pope's visit.

Leo, originally from Chicago, was chosen to lead the 1.4 billion-member Catholic Church last May after the death of Pope Francis.

He kept a relatively low profile in his first 10 months, but in recent weeks has become outspoken on a range of issues, and a firm critic of the U.S.-Israeli war against Iran.

POPE TRAVELLING NEARLY 18,000 KM ON AFRICA TOUR

Trump called the pontiff "terrible" on social media on Sunday, and doubled down on Tuesday night, despite widespread backlash from U.S. Christians across the political spectrum.

The pope told Reuters on Monday that he planned to keep criticizing the war, regardless of Trump's comments.

Leo, aged 70, relatively young for a pope and in good health, is undertaking one of the most complicated tours arranged for a pontiff in decades.

He is traversing nearly 18,000 km (11,185 miles) over 18 flights to 11 cities and towns and will also visit Angola and Equatorial Guinea.

The pope will travel on Thursday to Bamenda, Cameroon's largest English-speaking city, holding Mass and a "meeting for ​peace" in a cathedral.

The biggest event of Leo's tour will likely come in Cameroon on Friday, when the Vatican said some 600,000 are expected for a Mass in the coastal city of Douala.

-Reporting by Joshua McElwee; Editing by Robbie Corey-Boulet and Alex Richardson/Reuters