Saudi Arabia's King Salman, a key ally of Washington, has repeated accusations that Iran is exporting extremist Islamic movements to the world despite the Riyadh regime's terror record and its dismal background of human rights violations.

The Saudi king claimed in a televised speech on Sunday during a visit by US President Donald Trump to the kingdom that Iran's authorities represent the "tip of the spear" of global terrorism.

"Our responsibility before God and our people and the whole world is to stand united to fight the forces of evil and extremism wherever they are.... The Iranian regime represents the tip of the spear of global terrorism," the Saudi king claimed.

Elsewhere in his remarks, the Saudi monarch said, "We will never be lenient in trying anyone who finances terrorism, in any way or means, to the full force of the law."

Salman's anti-Iran accusations come at a time that Saudi Arabia is itself accused of sponsoring Takfiri terrorist groups such as al-Qaeda and Daesh in several Islamic countries.

Following suit with King Salman, the visiting US president also made a speech addressed to the Arab Islamic American Summit in Riyadh on Sunday in which Trump called for the international "isolation" of Iran.

"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, adding, "Until the Iranian regime is willing to be a partner for peace, all nations of conscience must work together to isolate it... and pray for the day when the Iranian people have the just and righteous government they so richly deserve."

Meanwhile, Iran's Foreign Minister Mohammad Javad Zarif, in an editorial for the website of the London-based Al Araby Al-Jadeed news network on Sunday, advised President Trump to discuss how to avoid another September 11 terrorist attack with the Saudi hosts of his first official visit abroad.

"(Trump) must enter into dialogue with them about ways to prevent terrorists and Takfiris from continuing to fuel the fire in the region and repeating the likes of the September 11 incident by their sponsors in Western countries," Zarif wrote.

Trump had earlier suggested that the Saudi kingdom might have been behind the September 11 attacks, noting, "You will find out who really knocked down the World Trade Center, because they have papers out there that are very secret. You may find it's the Saudis, okay, but you will find out."

The US president, however, has put an end to his sharp commentary in public about Riyadh, Washington's key ally, since his election.

US President Donald Trump speaks during the so-called Arabic Islamic American Summit at the King Abdulaziz Conference Center in Riyadh, Saudi Arabia, May 21, 2017. (Photo by AFP)

In April, Iraq’s Prime Minister Haider al-Abadi said during an interview with Lebanon’s Al Mayadeen television channel that the nationals of his country had good reason to believe Saudi Arabia was a state sponsor of terror. He added, “Many Saudi nationals have carried out terrorist operations in Iraq, and every Iraqi citizen has a right to believe that Saudi Arabia is a supporter of terrorism.”

Saudi Arabia’s official radical ideology of Wahhabism, which is known for its lack of tolerance, shapes up the mindset of Daesh and other terrorist groups worldwide. Daesh has been ravaging Iraq since 2014.

On the other hand, the Saudi regime and some other Arab monarchies of the Persian Gulf region stand accused of funding and arming anti-Damascus militants, Daesh in particular, who have been engaged in deadly violence in Syria since 2011.

Saudi Arabia is also furious about recent gains made by Syrian government troops against Takfiri terrorists supported by Riyadh.

Washington and Riyadh have both been sidelined in efforts led by Iran, Russia and Turkey aimed at bringing an end to the crisis in Syria.

Riyadh's fury is also understandable as Iraqi government forces and fighters from Popular Mobilization Units are expected to fully liberate the city of Mosul and will soon kick the Daesh Takfiri terrorists out of their last urban stronghold in Iraq.

In addition, Riyadh is under pressure by human rights groups to end its ongoing aggression against Yemen, which has killed more than 12,000 people, mostly civilians, since it began in March 2015.

Saudi Arabia has been incessantly pounding Yemen in an attempt to bring back to power Abd Rabbuh Mansur Hadi, the former Yemeni president, who has resigned and is a staunch ally of Riyadh, and to undermine the Houthi Ansarullah movement and secure its borders. The Riyadh regime has, however, failed to achieve its objectives despite going to great expense.

Riyadh has been purchasing tens of billions of dollars worth of arms from the US over the past years to use in Yemen war.

Moreover, Saudi Arabia has also lost its influence in Lebanon since Lebanese political parties announced their decision to form a national unity government and elected and backed Michel Aoun as president last year.

In recent months, senior Saudi officials have vowed to form a military alliance with Israel in order to counter Iran’s growing influence across the region.