US Vice President Joe Biden arrives in Beirut on Friday on the first such high-level US visit in nearly three decades, in a show of support for Lebanese independence just two weeks before a crucial election.
Biden will meet President Michel Sleiman, Prime Minister Fuad Siniora and parliament speaker Nabih Berri during his lightning trip, US and Lebanese officials said.
His visit, which comes on the heels of a trip to Kosovo, is aiming to "reinforce the United States? support for an independent and sovereign Lebanon," the White House said.
The June 7 vote pits the current US-backed parliamentary majority against an alliance headed by the Shiite fundamentalist movement Hezbollah which has the support of Syria and Iran.
The militant party, which fought a devastating war with Israel in 2006 and which is branded a terrorist outfit by Washington, and its allies stand a good chance of winning the majority of seats in parliament.
Such a scenario would force the United States to rethink its strategy towards Lebanon, a deeply divided nation which has endured decades of wars, political crises and political assassinations.
Biden will be the first sitting US vice president to visit the Mediterranean country since George Bush Senior came to Beirut in 1983 in the aftermath of the bombing of the US marine barracks that killed 241 troops.
Biden and Sleiman will both make a statement after their meeting, and Biden will also make an announcement on US military assistance to Lebanon with Defence Minister Elias Murr, the White House said.
Last month US Secretary of State Hillary Clinton also made a brief stop in Beirut, where she expressed Washington's support for a "free, independent and sovereign" Lebanon and called for the election to be held without any intimidation or outside interference.
A senior State Department official travelling with her said at the time: "If Hezbollah wins (the June vote), we will have to look at the composition of the government, and particularly at the programme, to evaluate ... what we are going to do in Lebanon."
Hezbollah officials say they have received assurances that the West does not envisage imposing the same sort of boycott it slapped on the Palestinians when a Hamas-led government took power in Gaza after an election in January 2006.
US President Barack Obama's administration has also been making efforts to repair its relationship with the Muslim world, including Syria and Iran.
But it has sought to reassure its allies in Beirut that any rapprochement with Damascus, which dominated Lebanon for nearly three decades, would not be at their expense.
Simon Karam, Lebanon's former ambassador to Washington, said the visits by Clinton and Biden could signal a shift in US policy in Lebanon.
"I think the United States is hedging its bets on the eve of this new term in Lebanese political life and signaling strongly that they will be investing in state institutions first and among these institutions, in the president," he told AFP.
"There is a serious chance that the opposition will turn into the majority on the eve of the election, and the US will in this case have to re-orient its engagement in Lebanon, and this visit could be one way for them to pave the way toward such a development," he added.