Hezbollah leader Sheikh Naim Qassem on Monday rejected Lebanon's planned direct talks with Israel, calling them a "grave sin" that will destabilize Lebanon, as he vowed to end the Israeli occupation of south Lebanon.

Qassem said Hezbollah will not give up its arms and people will return to their lands, vowing that Israeli troops will not remain on "a single inch of our occupied land".

Hezbollah has rejected Israeli Prime Minister Benjamin Netanyahu's accusation that it was jeopardizing a ceasefire and said it would keep responding to Israel's own violations and occupation of south Lebanon.

In a statement Sunday, Hezbollah said its attacks on Israeli targets in southern Lebanon and northern Israel were "a legitimate response to the enemy's persistent violations of the ceasefire since the first day of the announcement of the temporary truce".

Iranian Foreign Minister Abbas Araghchi on Monday blamed the United States for the failure of peace talks in Pakistan, after arriving in Russia for a meeting with President Vladimir Putin.

"The U.S. approaches caused the previous round of negotiations, despite progress, to fail to reach its goals because of the excessive demands," Araghchi was quoted as saying by Iranian state media.

The Israeli military said on Sunday that a soldier was killed in southern Lebanon, where a ceasefire has been in place since mid-April.

Sergeant Idan Fooks, 19, died "during combat" in south Lebanon, while "an officer and three additional soldiers were severely injured, along with a soldier who was moderately injured and a soldier who was lightly injured", the military said.

Lebanon's health ministry said Israeli strikes on the country's south on Sunday killed 14 people, the deadliest day since a ceasefire in the Israel-Hezbollah war came into force over a week ago.

It came as Israel and the Iran-backed group traded fresh accusations of breaching the fragile truce, with Prime Minister Benjamin Netanyahu saying the military was "vigorously" targeting Hezbollah and the group vowing to keep responding to "violations".

Israeli Prime Minister Benjamin Netanyahu on Sunday said Hezbollah's actions were threatening the ceasefire between Israel and Lebanon, as he pledged to "vigorously" target the Iran-backed group.

"It must be understood that Hezbollah's violations are, in practice, dismantling the ceasefire," Netanyahu said during a weekly cabinet meeting.

Lebanese official media said Israel's military began striking the country's south on Sunday after issuing an evacuation warning for seven locations, despite a ceasefire with Hezbollah.

"Israeli warplanes launched a strike" in Kfar Tibnit -- one of the locations included in the warning -- the state-run National News Agency said, adding that there were reports of casualties.

Iran's foreign minister was due to return to Pakistan on Sunday as international mediators try to keep peace talks on track despite U.S. President Donald Trump calling off his envoys' planned trip.

U.S. President Donald Trump said Saturday a shooting at the White House Correspondents' Association dinner would not deter him from the Iran war, although he believed the incident was unlikely linked to the conflict.

International efforts to mediate between the United States and Iran were in the balance on Sunday, after President Donald Trump canceled his envoys' planned trip to Pakistan for talks.