Hariri's first official visit to the United States takes place against a backdrop of tensions in the Middle East, US efforts to restart Israeli-Palestinian peace talks and growing momentum toward new international sanctions on Iran.
Analysts expect Obama to be more encouraging in tone than demanding of results when he meets Hariri, who heads a national unity government that includes Hezbollah - a Shiite Islamist group which is backed by Syria and Iran and is listed as a terrorist organization by the United States.
White House spokesman Robert Gibbs said on Friday the two leaders would discuss a "broad range of mutual goals in support of Lebanon's sovereignty and independence, regional peace and security."
Lebanon and Syria have said they fear a possible attack by the Jewish state after its president, Shimon Peres, accused Syria in April of supplying Hezbollah with long-range Scud missiles capable of hitting Israel. Damascus has denied the charge and accused Israel of fomenting war.
Some US officials have expressed doubt that any Scuds were actually handed over in full to Hezbollah, although they believe Syria might have transferred weapons parts.
"We obviously have grave concerns about the transfer of any missile capability to Hezbollah through Lebanon from Syria," a senior Obama administration official told Reuters, saying the issue would likely be raised in Monday's talks.
Another official said Washington would ask Hariri to continue to support efforts "toward comprehensive regional peace."
Hariri has also denied Israel's accusations, while his government has said it backs the right of the group to keep its weapons to deter Israeli attacks. Israel, which fought a 34-day war with Hezbollah in 2006, has not signaled any imminent plans to strike.
The war of words heightened tensions in the region, but the UN Special Coordinator for Lebanon, Michael Williams, noted on Friday "that recent tension is now diminishing."
Williams, who held talks with Hariri in Beirut, was quoted by the prime minister's office as saying he was pleased "that all sides have scaled back the rhetoric."
Obama and Hariri are also expected to discuss US-led international efforts to isolate Iran over its disputed nuclear program, officials said. Lebanon holds the rotating presidency of the UN Security Council through May 31.
Diplomats said Beirut had quietly asked the permanent members of the Security Council - Britain, France, Russia, China and the United States - not to push for a vote on a new Iran sanctions resolution while it held the presidency.
Lebanon is expected to abstain in any vote because Iranian-backed Hezbollah is in its government, diplomats said.