US President Donald Trump on Sunday urged Islamic leaders to take a stand against violence done in the name of religion, describing the struggle against extremism as a “battle between good and evil”.

Explore: The Saudi temptation

In a highly anticipated speech in Saudi Arabia, Trump lashed out at Iran, accusing Tehran of fuelling “the fires of sectarian conflict and terror” and calling for its international isolation.

Saying he came with “a message of friendship and hope and love”, Trump told dozens of Muslim leaders that the time had come for “honestly confronting the crisis of religious extremism”.

“This is a battle between barbaric criminals who seek to obliterate human life, and decent people of all religions who seek to protect it. This is a battle between good and evil.”

The speech came on the second day of a visit to Saudi Arabia, part of Trump's first foreign tour that will take him next to Israel and the Palestinian territories and then to Europe.

The White House has sought to draw a clear distinction during the visit with Trump's predecessor Barack Obama, who Saudi Arabia and its Arab allies saw as lecturing and soft on their rival Iran.

Trump did not hesitate to single out Iran in his speech.

“From Lebanon to Iraq to Yemen, Iran funds, arms and trains terrorists, militias and other extremist groups that spread destruction and chaos across the region,” Trump said.

“Until the Iranian regime is willing to be a partner for peace, all nations of conscience must work together to isolate it.” He appealed to Muslim nations to ensure that “terrorists find no sanctuary on their soil” and announced an agreement with Gulf countries to fight financing for extremists.

Introducing Trump, Saudi King Salman called Iran “the spearhead of global terrorism”.

Unlike the Obama administration which would often raise concerns over civil liberties with longstanding Arab allies, Trump had made no mention of human rights during his visit so far.

“We are not here to lecture — we are not here to tell other people how to live... or how to worship. Instead, we are here to offer partnership — based on shared interests and values,” Trump said.

Some 35 heads of state and government from Muslim-majority countries were in Riyadh for the Arab Islamic American Summit, mainly from states friendly to Saudi Arabia.

Much of the focus during the summit was on countering what Gulf states see as the threat from Iran, which opposes Saudi Arabia in a range of regional conflicts from Syria to Yemen.

'Tremendous' first day

Trump's speech was touted as a major event — along the lines of a landmark address to the Islamic world by Obama in Cairo in 2009.

It was especially sensitive given tensions sparked by the Trump administration's attempted travel ban targeting several Muslim-majority nations and his previous remarks on Islam.

In December 2015, Trump told a campaign rally he was calling for a “total shutdown” of Muslims entering the United States “until our country's representatives can figure out what the hell is going on”.

His words shocked many Americans, with Trump detractors noting that the US Constitution prohibits religious discrimination.

“I think Islam hates us. There is a tremendous hatred there. We have to get to the bottom of it,” Trump said in a March 2016 interview with CNN.

Still, Trump was welcomed warmly in Saudi Arabia, where he and first lady Melania Trump were given an extravagant reception by King Salman and the rest of the Saudi royal family.

The first day saw the announcement of hundreds of billions of dollars in trade deals, welcome news for Trump as he faces mounting troubles at home linked with the probe into alleged Russian meddling during last year's election campaign.

Among the agreements was an arms deal worth almost $110 billion with Saudi Arabia, described as the largest in US history.

The trade deals announced on Saturday were said to be worth in excess of $380 billion, and Trump proudly declared the first day of his visit “tremendous”.

On Sunday he held a series of meetings with other Arab leaders, including Egyptian President Abdel Fattah al-Sisi, Qatar's Emir Sheikh Tamim bin Hamad Al-Thani and Bahrain's King Hamad.

Warm talks with 'friend' Sisi

The meeting with Sisi — an avowed fan of the president — was especially warm and Trump said he would “absolutely” be putting Egypt on his list of countries to visit “very soon”.

Trump referred to Sisi as “my friend” and Sisi said the US president was a “unique personality” and “capable of doing the impossible”, to which Trump responded: “I agree!” Trump even complimented Sisi on his footwear, saying: “Love your shoes.

Boy, those shoes. Man...” Sisi has faced harsh criticism of his human rights record since he led the military overthrow of Islamist predecessor Mohamed Morsi in 2013.

Trump, who travels on Monday to Israel and the Palestinian territories before visiting the Vatican, Brussels and Italy for Nato and G7 meetings, is taking his first steps on the world stage as he faces increasing scandal at home.

The last week has seen a string of major developments in Trump's domestic woes, including the announcement that James Comey, the former FBI chief fired by Trump, has agreed to testify publicly about Russian interference in the US elections.

Reports have also emerged that Trump called Comey “a nut job” and that the FBI has identified a senior White House official as a “significant person of interest” in its probe of Russian meddling.