Saudi Arabia's king personally welcomed Iranian President Mahmoud Ahmadinejad upon his arrival Saturday, a rapprochement many hope will help calm sectarian tensions threatening the Middle East.

King Abdullah received Ahmadinejad at the airport, and the two were expected to begin talks immediately, the official Saudi Press Agency news agency reported.

Ahmadinejad's trip comes amid rapid developments that threaten to further isolate his country and place it under punitive sanctions because of its refusal to suspend uranium enrichment.

On Saturday, top diplomats from the United States, Russia, China, Britain, France and Germany will try to reach agreement on new sanctions against Iran. A U.S. official predicted the session would lead to a "substantive resolution."

The push for new sanctions follows an International Atomic Energy Agency report in late February that Iran was expanding enrichment instead of suspending it.

At the same time, the U.S. has been beefing up its military presence in the Gulf in the past two months. Although Washington has said it has no plans to strike Iran, it has also refused to rule out any option.

Regionally, most Arab governments, which are overwhelmingly Sunni, have signaled impatience and worry over mostly Shiite Iran's backing of co-religionists in Iraq and Lebanon, saying such support can only destabilize the region.

Iran is a strong backer of Lebanon's Hezbollah, which is striving to bring down the U.S.- and Saudi-backed Lebanese government. Iran also has close ties to Shiite political parties in Iraq, and Washington accuses it of backing Shiite militias there.

Arab officials have pointed out that while Shiites are a majority in Iran and Iraq, they make up only 15 percent of the world's Muslim population, and sectarian tensions could ultimately work against the groups which Iran supports.

Saudi newspapers, which are government-guided, struck a welcoming tone in editorials, saying they hoped Ahmadinejad's visit signals an Iranian willingness to revise its regional policies and work with, rather than against, Arab governments.

"We wish you the very best on your first official visit to Saudi Arabia," said Saudi Gazette.

The paper said the challenge facing the two countries is how to unite the Islamic world, which is in danger of fragmenting because of sectarian tensions.

"How did we ever allow ourselves to slip into this situation? What good is our (the Islamic world's) common cause if we waste our energies and resources on self-destruction rather than self-preservation?" said the paper.

Ghassan Sharbil, the Lebanese editor of the Saudi-owned Al-Hayat daily, described the visit as "exceptional" and said Ahmadinejad can, if he wants to, turn it into an opportunity for his country.

"Iran has proved its capability of destabilization ... cold and hot objections," wrote Sharbil. "Now, it's time to prove its ability to participate in creating stability."

"Ahmadinejad can invest in this summit to calm down the Arab world, the Islamic world and the whole globe in order to protect Iran against isolation, the dangers of an American strike and a new resolution by the Security Council."

Iranian newspapers only published official reports that Ahmadinejad will be visiting Saudi Arabia later Saturday.

Just one newspaper included some opinion in its report. The independent daily "Tehran-e-Emrooz," or Today's Tehran, said Ahmadinejad's administration is seeking improved ties with Saudi Arabia to increases chances of resolving the Middle East conflict without much U.S. intervention and at the same time ease Saudi worries over Iran's nuclear activities.

"Trying to help improve cool relations between Saudi Arabia and Syria to resolve the Lebanese crisis ahead of the Arab League meeting is another goal of Ahmadinejad's visit to Saudi," the paper said.