Saudi Arabia promised “assistance in all areas” for Lebanon when Crown Prince Mohammed bin Salman invited Lebanese President Joseph Aoun to Riyadh in a call on Monday.
The call from Prince Mohammed, announced by both governments early in the day, came at a critical time for Mr Aoun during his visit to the US and a day before meeting President Donald Trump.
Prince Mohammed reiterated his “determination to provide assistance in all areas needed by Lebanon, in line with the priorities set by the Lebanese government”, Mr Aoun's office said.
But what that assistance could amount to remains vague, as do Saudi Arabia's immediate intentions for Beirut. In June, Prince Mohammed ordered the resumption of Lebanese exports to the kingdom after a ban lasting nearly five years.
"Saudi Arabia is with the Washington track and supports these meetings taking place," said a Lebanese politician close to the Saudis.
"[Prince Mohammed] could have made the call before the President traveled to the USA. Not only did he make a call but he also invited [President Aoun] to Saudi Arabia," they added, suggesting this showed Riyadh's approval.
During Monday's call, Prince Mohammed and Mr Aoun “reviewed the latest developments in Lebanon and the region, and the efforts being made to enhance security and stability”, said a statement by the Saudi Press Agency.
Saudi Arabia – along with other Gulf partners – was a once vital economic donor to Lebanon, but moved away amid the perceived growing influence of Iran and Hezbollah over Lebanese affairs.
Even before the latest round of war erupted between Israel and Hezbollah this year, major international donors such as Saudi Arabia had already conditioned the billions of dollars reconstruction funds requested by Beirut on progress on disarming Hezbollah.
Mr Aoun is seeking backing during his US visit for the start of Israel's withdrawal from south Lebanon.
Prince Mohammed's call with Mr Aoun came after the Lebanese President met US Secretary of State Marco Rubio.
Mr Aoun stressed the “necessity” of the US supporting Lebanon's underfunded army and encouraged American investment in energy, communications and transport.
His courting of deeper support from Israel's most powerful ally is likely to further provoke discord among his domestic detractors.
A US State Department statement on Sunday about the call focused largely on the Lebanese government's plan to disarm Hezbollah and did not directly mention Israel's withdrawal.
Lebanon is seeking to show that it is ready to take over positions occupied by Israel. On Monday the US State Departement said the 'pilot zone'process - whereby the Israelis withdraw from specified zones and the Lebanese Army takes over - had begun.
However, Lebanon has repeatedly stressed that two of the three villages in the first pilot zones were empty of Israeli soldiers as it was.
It is hoped that Mr Aoun's meeting with President Trump at the White House on Tuesday will provide more clarity.
The security official said “really, nobody knows” what could come out of the meeting. “Of course it's an important meeting and we wait for it,” the official added.
Mr Aoun left Beirut seeking US guarantees that Washington will press Israel to implement the agreement signed on June 26, along with commitments towards an imminent Israeli withdrawal from Lebanese territory.
Lebanese officials have repeatedly emphasised that they are waiting for Israel to start the process, withdraw from agreed positions and allow the Lebanese Army to consolidate control.
The visit, Mr Aoun's first to Washington since taking office last year, follows two days of US-mediated talks in Rome that ended without a timetable for the agreement to be implemented.
Rather than beginning a withdrawal, Israel has continued to bed down in areas it controls in south Lebanon.
A handful of Israeli settlers have also breached the border and entered Lebanese territory occupied by Israel in recent days.
Lebanese MP Melhem Khalaf, a former president of the Beirut Bar Association and an international legal expert, said such acts were not merely “a border incident” but “a direct aggression against the sovereignty of the Lebanese Republic”.
