Saudi Arabia's decision to invite Prime Minister Saad Hariri and not President Michel Aoun to an Arab-Islamic summit in Riyadh with U.S. President Donald Trump has stirred controversy in Lebanon, media reports said on Friday.

Hariri was handed the invitation on Thursday by the Chargé d'affaires of the Saudi Embassy in Lebanon, Walid Al-Bukhari.

“Several Lebanese leaders and officials said the invitation involved a flagrant diplomatic and protocol mistake, especially that the summit will be held at the level of presidents and kings, and accordingly the invitation should have been addressed to Lebanon's president and not to any other Lebanese official,” al-Joumhouria newspaper reported.

Observers have noted that Lebanon's Christian presidents had taken part in several Islamic summits in the past, the daily said.

“Lebanese diplomacy is trying to seek answers and clarifications regarding this step,” al-Joumhouria added.

“The possibility of correcting this mistake through addressing an invitation to the president is not ruled out,” the daily quoted sources as saying.

“Should Hariri decide to participate, he might clash with the president over the step, while his failure to participate might put him in an embarrassing situation with the summit's hosts and participants,” observers said.

But citing reports, al-Joumhouria said that the prime minister has not yet responded to the invitation and that he intends to consult with the president over it.

“The aim of the summit is to work towards the establishment of a new partnership to confront extremism and terrorism and reinforce the values ​​of tolerance and better living for the future of our generations in the Arab region,” the Saudi envoy said on Thursday.

The summit will be attended by U.S. President Trump during his upcoming visit to the kingdom.

Saudi media said King Abdullah II of Jordan, Algerian President Abdelaziz Bouteflika and Niger's Mahamadou Issoufou are among leaders invited by King Salman for the summit with the U.S. president.

Trump has frequently been accused of fueling Islamophobia but aides described his decision to visit Saudi Arabia as an effort to reset relations with the Muslim world.

In addition to heads of state from Jordan, Algeria and Niger, the official Saudi Press Agency reported that Salman asked Yemeni President Abedrabbo Mansour Hadi and Morocco's King Mohammed VI to attend.

The leaders of Turkey, Pakistan, Iraq and Tunisia have also received invitations, the Arab News daily reported on Wednesday.

Saudi Arabia -- which is home to Islam's holiest sites -- will be Trump's first foreign stop since becoming president in January.