By Emma Farge

GENEVA, March 20 (Reuters) - The outgoing head of the U.N. Palestinian refugee agency has warned that the viability of the organisation is in doubt, a letter showed on Friday, saying any collapse would result in Israel taking over its humanitarian work in Gaza.

The warning from Philippe Lazzarini comes at a decisive moment for the agency, which has suffered from major funding problems for months, with no permanent replacement yet appointed ahead of his departure on March 31.

By Uditha Jayasinghe

COLOMBO, March 20 (Reuters) - Sri Lanka declined permission for two U.S. combat aircraft to land at a civilian airport earlier this month, President Anura Kumara Dissanayake told parliament on Friday.

The U.S. had requested permission for the two aircraft to land at the Mattala Rajapaksa International Airport in the southern part of the country from March 4-8, Dissanayake told lawmakers.

"They wanted to bring two warplanes armed with eight anti-ship missiles from a base in Djibouti," he said during a statement.

March 20 (Reuters) - Switzerland on Friday said it would not issue licences for companies to export weapons to the United States due to the ongoing attacks on Iran, citing the country's neutrality.

"The export of war materiel to countries involved in the international armed conflict with Iran cannot be authorised for the duration of the conflict," the government said in a statement.

"Exports of war materiel to the USA cannot currently be authorised," it added.

AMSTERDAM, March 20 (Reuters) - The Netherlands is stepping up security for Iranian dissidents living in the country after a man of Iranian descent who is known to be critical of the authorities in Tehran was shot, Dutch Justice Minister David van Weel said on Friday.

A spokesperson for Van Weel declined to provide more details.

KYIV, March 20 (Reuters) - Ukraine has deployed interceptor units to protect critical and civil infrastructure in five Middle Eastern countries, Ukraine's security council secretary Rustem Umerov said after a visit to the region.

"Work is also underway to expand coverage areas," Umerov wrote on X.

(Reporting by Yuliia Dysa, writing by Max Hunder, Editing by William Maclean)

"We were attacked," wrote a sailor in the Strait of Hormuz, the crucial waterway blocked for weeks since US-Israeli strikes triggered a war with Iran, in a group chat seen by AFP on Friday.

The conversations in Chinese on the messaging app WeChat -- provided by a worker whose ship has been stuck in the Gulf since the conflict started -- paint a vivid picture of the perils now facing sailors there, who hail from around the world.

Hundreds of Muslim worshippers held Eid prayers at the gates of Jerusalem's Old City Friday, with Israel closing access to the Al-Aqsa mosque and other holy sites over the war with Iran.

"Today, Al-Aqsa has been taken from us. It's a sad and painful Ramadan," Wajdi Mohammed Shweiki, a silver-haired Palestinian man in his 60s, told AFP.

"It's a catastrophic situation for the inhabitants of Jerusalem, for Palestinians in general and for all Muslims across the globe."

By Rajesh Kumar Singh

CHICAGO, March 20 (Reuters) - U.S. airline chiefs are talking about the U.S.-Israeli war on Iran in a way that many of their counterparts overseas are not — projecting confidence about fares and demand even as fuel costs surge and global aviation is disrupted.

For the biggest U.S. carriers, which do not hedge against oil price rises, the shock is showing up mainly in the fuel bill, with jet fuel prices nearly doubling since the conflict began in late February.

Forced by yet another war in Lebanon to flee his home for the second time in just two years, and mourning lost relatives and friends, Hassan Kiki said he feels much older than 16.

"War has aged us... We have lived through what no one else has," the tall teen from south Lebanon told AFP in Beirut.

"I miss my school, my friends... I lost two cousins and two friends in a massacre in Shehabiyeh," he added, referring to a deadly Israeli strike in his town that killed at least seven people on March 11.

March 20 (Reuters) - The Trump administration is considering plans to occupy or blockade Iran's Kharg Island to pressure Iran to reopen the Strait of Hormuz, Axios reported on Friday, citing four sources with knowledge of the issue.

(Reporting by Rishabh Jaiswal in Bengaluru, Editing by William Maclean)