Top US and Russian diplomats will meet in Saudi Arabia on Tuesday for talks on resetting the countries' fractured relations and making a tentative start on trying to end the Ukraine war.

Both sides played down the chances that the first high-level meeting between the countries since Moscow invaded Ukraine in 2022 would result in a breakthrough.

Nevertheless, the very fact of the talks has triggered concern in Kyiv and Europe -- left reeling by Washington's dramatic diplomatic moves towards the Kremlin.

Five men went on trial in France on Monday charged with holding four French journalists hostage for the Islamic State jihadist group in war-torn Syria more than a decade ago.

IS emerged in 2013 in the chaos that followed the outbreak of the Syrian civil war, slowly gaining ground before declaring a caliphate in large parts of Syria and neighbouring Iraq.

The jihadists abducted a number of foreign journalists and aid workers before US-backed forces eventually defeated the group in 2019.

Holding pictures of their loved ones, families of Israeli hostages held in Gaza marked 500 days of captivity on Monday, urging authorities to secure their release.

Dozens of demonstrators were seen marching to Prime Minister Benjamin Netanyahu's residence in Jerusalem, chanting slogans and carrying banners that read "Home Now", before meeting lawmakers in parliament.

"My eyes burn from the tears I have shed for the past 500 days," said Einav Tzangauker, whose son Matan is among those still held captive since Hamas's October 7, 2023 attack on Israel that sparked the Gaza war.

The head of the World Health Organization insisted on Monday it was "now or never" to strike a landmark global accord on tackling future pandemics, after the United States withdrew from negotiations.

WHO director-general Tedros Adhanom Ghebreyesus said no country could protect itself from the next pandemic on its own -- three days after US President Donald Trump's administration told the UN health agency it was leaving the pandemic agreement talks.

A Lebanese official said Israeli troops had started withdrawing Monday from some border villages, after Israel's military said it would remain in five "strategic points" hours before a ceasefire deadline to pull out.

Earlier, Lebanon's president voiced concern that Israel would miss the Tuesday deadline under the ceasefire between Israel and Hezbollah, and urged countries to pressure it to honour the cut-off.

Israel expressed commitment on Monday to a US proposal to take over Gaza and displace its Palestinian residents, as Washington's top diplomat held talks in Saudi Arabia where he was expected to push the plan opposed by Arab states.

Arriving in the kingdom after talks in Israel, Secretary of State Marco Rubio -- on his first visit to the Middle East -- met de facto ruler Crown Prince Mohammed bin Salman, the State Department said.

Hezbollah's chief said Sunday it was the government's responsibility to ensure the Israeli army withdraws from Lebanon by a looming ceasefire deadline, as Israel carried out air strikes in the country.

The developments came as US Secretary of State Marco Rubio, speaking from Jerusalem, called on Lebanon to disarm Hezbollah following its recent war with Washington's closest regional ally Israel.

Lebanon's National News Agency (NNA), meanwhile, reported Israeli forces opened fire towards the southern border town of Hula "after residents entered", killing a woman.

Israel's security cabinet was set to discuss on Monday the next phase of the ceasefire in Gaza, after top US diplomat Marco Rubio and Israeli leader Benjamin Netanyahu presented a united front against Hamas and Iran.

Rubio was in Israel on his first Middle East trip as President Donald Trump's secretary of state, and was slated to leave for Saudi Arabia on Monday.

US Secretary of State Marco Rubio arrived in Israel late Saturday on the first leg of a Middle East tour, an AFP journalist reported.

Rubio landed at Ben Gurion Airport in Tel Aviv and is due to hold talks with Israeli officials on Sunday when he will highlight President Donald Trump's controversial proposal to take control of the Gaza Strip, which has been devastated by more than 15 months of war between Hamas and Israel.

Amanda Anisimova clinched the first WTA 1000 title of her career with a 6-4, 6-3 victory over Jelena Ostapenko in a rain-interrupted Qatar Open final on Saturday.

At 41 in the world, Anisimova is the lowest-ranked champion in tournament history and the first American to triumph in Doha since Monica Seles lifted the trophy in 2002.

Ostapenko was coming off a resounding victory over three-time champion and world number two Iga Swiatek in the previous round but Anisimova gave the Latvian a taste of her own medicine, showcasing incredible ball-striking and precision.