By Trevor Hunnicutt and Kanishka Singh

WASHINGTON, Jan 20 (Reuters) - U.S. President Donald Trump said on Tuesday "you got to let the U.N. continue" when asked about his plans for a so-called "Board of Peace" that has alarmed international experts.

Governments around the world have reacted cautiously to Trump's invitation to join that initiative that the U.S. president says aims to resolve conflicts globally, a plan that diplomats said could harm the work of the United Nations.

By Dave Graham and Francois Murphy

DAVOS, Switzerland, Jan 20 (Reuters) - The standoff with Iran over accounting for its stock of highly enriched uranium and inspecting nuclear facilities bombed by the United States and Israel cannot go on forever, U.N. nuclear watchdog chief Rafael Grossi said on Tuesday.

The world is entering an era of "global water bankruptcy" with rivers, lakes and aquifers depleting faster than nature can replenish them, a United Nations research institute said on Tuesday.

It argues that decades of overuse, pollution, environmental destruction and climate pressure had pushed many water systems so beyond the point of recovery that a new classification was required.

Like other exiled Iranians, chess champion Mitra Hejazipour has been scouring social media for news about anti-government protests in her homeland and battling to reach friends and family through an ongoing internet shutdown.

The 32-year-old is one of the greatest chess players Iran has ever produced, but she fled to France five years ago after removing her mandatory headscarf during a competition in Moscow.

Hundreds of Israeli ultra-Orthodox Jews protested on Tuesday to voice their religious objections to planned autopsies of two babies who died in an incident at an unlicensed nursery in Jerusalem a day earlier.

Israeli doctors declared the babies dead after medics evacuated 55 children from the daycare centre in an area of Jerusalem inhabited by members of the ultra-Orthodox community, though they have not yet specified a cause of death.

By Ismet Mikailogullari

NUSAYBIN, Turkey, Jan 20 (Reuters) - Turkey said on Tuesday it was investigating the burning of its flag during protests along its border with Syria by pro-Kurdish groups, coinciding with clashes there between the Damascus government army and Kurdish-led forces.

Jan 20 (Reuters) - Syria's defence ministry announced a four-day ceasefire following a new agreement with the Kurdish-led Syrian Democratic Forces (SDF), starting from 2000 local time on Tuesday.

(Reporting by Jaidaa Taha and Muhammad Al Gebaly)

WASHINGTON, Jan 20 (Reuters) - About 200 low-level Islamic State fighters escaped Syria's Shaddadi prison on Monday after guards from the Kurdish-led Syrian Democratic Forces left the facility, but Syrian government forces recaptured many of them, a U.S. official said on Tuesday.

The official, speaking to Reuters on condition of anonymity, said about 600 foreign fighters from Islamic State had been transferred from Shaddadi prior to January 19 to other facilities and remain in detention.

(Reporting by Phil Stewart and Idrees Ali; Editing by Lisa Shumaker)

DUBAI, Jan 20 (Reuters) - The United Arab Emirates (UAE) accepted an invitation to join U.S. President Donald Trump's newly proposed “Board of Peace,” the UAE foreign ministry said on Tuesday, placing Abu Dhabi among the first governments to publicly endorse the initiative.

The ministry said the UAE stood ready to “contribute actively to the mission of the Board of Peace, supporting greater cooperation, stability, and prosperity for all,” marking Abu Dhabi's formal alignmentwith Washington’s new conflict‑resolution effort.

Iran has been pressing ahead with arrests following a wave of protests, according to local media and monitors, as the country faces international pressure over a crackdown rights groups said led to thousands of deaths under cover of ongoing internet restrictions.

Here are key developments:

- Arrests -

Iranian state media continues to regularly report arrests of people it says were part of a "terrorist operation" spurred by Tehran's arch foes Israel and the United States.