A senior US adviser has arrived in Lebanon on a two-day visit that coincides with a trip by Iranian Foreign Minister Hossein Amirabdollahian.
US energy adviser Amos Hochstein's arrival comes after Lebanon recently began drilling for oil and gas in the Block 9 area of its territorial waters.
Hochstein brokered a deal between Lebanon and its foe Israel last year that demarcated the two countries' maritime borders, without which the exploratory drilling could not have begun.
A statement from the US embassy in Beirut : "Senior Adviser to President Biden Amos Hochstein will travel to Lebanon August 30–31 to follow up on the historic October 2022 Maritime Boundary Agreement.
"Hochstein will also discuss areas of mutual and regional concern."
The trip comes as Iranian Foreign Minister Amirabdollahian was also due to visit Lebanon.
Tehran's ambassador to Lebanon, Mojtaba Amani, announced on Tuesday that the minister would arrive the following day.
"On his agenda are discussions and meetings with Lebanese officials on issues of common interest," Amani posted on the social media platform X, formerly called Twitter.
"This visit reflects Iranian policy and its constructive role supporting the stability and prosperity of Lebanon."
A source close to Lebanese Parliament Speaker Nabih Berri told °®Âþµº's Arabic sister service Al-Araby Al-Jadeed that Abdollahian and Berri would meet on Thursday.
The two sides will discuss "diplomatic, political and regional relations", said the source, who called the Iranian foreign minister's trip "important".
Amirabdollahian and Hochstein's visits come amid controversy over a UN Security Council vote due to take place Wednesday on renewing the UNIFIL peacekeeping force's mandate in Lebanon.
The United Nations Interim Force in Lebanon (UNIFIL) had its mandate extended last year with a slight modification criticised by Hezbollah leader Hassan Nasrallah at the time and again this week.
"A foreign armed force that moves on Lebanese territory without authorisation of the government and Lebanese army, without coordination with the Lebanese army, where is the sovereignty in all that?" Nasrallah said on Monday.
Under the modified mandate the peacekeeping force "is allowed to conduct its operations independently", the UN resolution said.
UNIFIL was first deployed more than four decades ago. It has routinely coordinated patrols and movements in its area of operations in the south with the Lebanese army.
But Lebanon's government has also objected to the absence, in the UN resolution, of a stipulation that such coordination takes place.
Hochstein and Abdollahian's trips also come as French envoy Jean-Yves Le Drian is expected to visit Lebanon next month.
While a date has not been set, Le Drian is working to find a solution to a political deadlock that has seen Lebanon without a president since October.
Amirabdollahian recently visited Saudi Arabia after Riyadh re-established diplomatic ties with Iran earlier this year.
Officials in Lebanon hope their country will also benefit, particularly when it comes to the presidential crisis.
Lebanon is particularly sensitive to regional developments and especially movements in the Saudi-Iranian relationship.
Agencies contributed to this report.