BEIRUT (Reuters) - U.S. Secretary of State Rex Tillerson warned Lebanon on Thursday that the Iran-backed Hezbollah group’s growing arsenal and involvement in regional conflicts threatened Lebanon’s security.

U.S. Secretary of State Rex Tillerson gestures as he talks during a joint news conference with Lebanon's Prime Minister Saad al-Hariri at the governmental palace in Beirut, Lebanon, February 15, 2018. REUTERS/Mohamed Azakir

Speaking alongside Lebanese Prime Minister Saad al-Hariri in a Beirut news conference, Tillerson also said the United States was engaging with Lebanon and Israel to ensure their border remained calm.

Israel regards Hezbollah as the biggest direct threat on its borders and has repeatedly struck it in Syria, where the group is fighting alongside President Bashar al-Assad in a civil war now entering its eighth year.

The Trump administration has taken a hardline position on Iran and has sanctioned several people and entities associated with Hezbollah in recent weeks as part of an effort to increase pressure on Iran.

The heavily armed Shi’ite movement is part of the Lebanese coalition government led by Sunni Muslim politician Hariri, under a complex political system that promotes sectarian power-sharing.

“Hezbollah is not just a concern for the United States. The people of Lebanon should also be concerned about how Hezbollah’s actions and its growing arsenal bring unwanted and unhelpful scrutiny on Lebanon,” Tillerson said.

“Hebollah’s entanglement in regional conflicts threatens the security of Lebanon,” he added.

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Hezbollah has always rejected any demand that it give up its weapons, which it says are necessary to defend Lebanon against Israel. It has said its role in Syria is needed to stop any Sunni militant threat to Lebanon, and said in January it believes the war there will be over in one or two years.

Tillerson’s visit, the first by a U.S. Secretary of State to Lebanon since 2014, got off to an awkward start as he waited several minutes in Baabda Palace for his meeting with President Michel Aoun, a Hezbollah ally.

The Lebanese president’s office denied any departure from diplomatic protocol and said Tillerson had arrived a few minutes early. Footage of him waiting aired on some Arabic TV channels throughout the day. Aoun later said Tillerson had listened and understood the Lebanese position regarding the Israeli border.

Israeli-Lebanese tensions have spiked in recent months because of Israeli plans to build a wall at the border, and because of Lebanon’s decision to begin exploring for oil and gas in an offshore block in disputed waters.

Hezbollah, which the United States deems a terrorist organization, has increased its military strength since the last major conflict with Israel in 2006.

Tillerson urged Lebanese leaders to uphold the country’s commitment to staying out of regional conflicts.

Israel has accused Iran of seeking to set up weapons factories in Lebanon, and the Israeli military last month said the country had turned into one “large missile factory”.

Lebanon is a big recipient of U.S. military support. Tillerson said Washington remained committed to supporting the Lebanese army and internal security forces.

When asked about the maritime border dispute with Israel, including Lebanese media reports that Washington had asked Beirut to give up a portion of sea it claims, Tillerson denied the reports.

“We will continue to be very engaged with both parties. We’ve asked no one to give up anything, rather we are looking for a solution,” he said. “We are engaging the governments of both Lebanon and Israel to ensure Lebanon’s southern border remains calm.”