By Ece Toksabay and Daren Butler

ISTANBUL, Jan 19 (Reuters) - A deal under which Kurdish forces abandoned long-held territory in Syria to the Syrian government could pave the way for Turkey to advance its stalled effort to end its decades-long conflict with the PKK, Turkish politicians and officials said on Monday.

Syrian President Ahmed al-Sharaa and US President Donald Trump discussed guaranteeing Kurdish rights in a phone call on Monday, Syria's presidency said, a day after Damascus reached a deal with Kurdish forces including a truce.

Sharaa met Mazloum Abdi, head of the Kurdish-led Syrian Democratic Forces, to discuss the agreement, which includes integrating the Kurds' administration into the state, but a Kurdish source with knowledge of the talks told AFP they were not positive.

The humanitarian crisis in Yemen is set to get much worse in 2026 as food insecurity increases and international aid evaporates, the United Nations warned on Monday.

Julien Harneis, the UN resident and humanitarian coordinator for Yemen, said he feared the calamitous situation would go under the radar until the death toll mounts.

The picture in Yemen is "very, very concerning", he told reporters in Geneva.

Last year, 19.5 million people in the country needed humanitarian aid -- and the UN's response plan for the country was only 28-percent financed, at $688 million.

Jan 19 (Reuters) - The Kurdish-led Syrian Democratic Forces said on Monday that an "armed group" was attacking Shaddadi prison in Hasaka in Syria's northeast where it said thousands of Islamic State militants were being held.

The SDF had said earlier in the day it was clashing with Syrian government forces near Al-Aqtan prison on the outskirts of the city of Raqqa that also held IS detainees. Raqqa was once the seat of a short-lived IS-declared "caliphate" in the region.

By Olivia Le Poidevin

GENEVA, Jan 19 (Reuters) - The U.N. warned on Monday that the humanitarian situation in Yemen is worsening and that gains made to tackle malnutrition and health would go into reverse due to funding cuts.

"The context is very concerning... We are expecting things to be much worse in 2026," Julien Harneis, U.N. Resident and Humanitarian Coordinator for Yemen, told reporters in Geneva.

US President Donald Trump's government has asked countries to pay $1.0 billion for a permanent spot on his "Board of Peace" aimed at resolving conflicts, according to its charter, seen Monday by AFP.

The White House has asked various world leaders to sit on the board, chaired by Trump himself, including Russian President Vladimir Putin, Hungarian premier Viktor Orban and Canadian Prime Minister Mark Carney.

JERUSALEM, Jan 19 (Reuters) - Israeli Finance Minister Bezalel Smotrich urged Prime Minister Benjamin Netanyahu on Monday to shut a U.S.-led multinational coordinating centre that supports President Donald Trump’s plan to end the Gaza war.

Washington established the Civil Military Coordination Centre (CMCC) last October as a centre for civilian and military personnel from other countries to work alongside U.S. and Israeli officials on post-war Gaza planning.

By Karam al-Masri and Khalil Ashawi

RAQQA/ Syria, Jan 19 (Reuters) - Syrian government troops tightened their grip on Monday across a swathe of northern and eastern territory abruptly abandoned the previous day by Kurdish forces, in a dramatic shift that consolidated President Ahmed al-Sharaa's rule.

After days of fighting with government forces, the Kurdish-led Syrian Democratic Forces (SDF), once the main U.S. allies in Syria, agreed on Sunday to withdraw from two Arab-majority provinces they had controlled for years, including oil fields.

ANKARA, Jan 19 (Reuters) - Turkish security sources said on Monday that an integration deal between Syria's government and Kurdish forces marked an "historic turning point" ahead of which Turkey's intelligence agency played an intensive role to ensure restraint by parties on the ground.

The fight against Islamic State in Syria would continue uninterrupted, the sources said, adding that establishing stability and security in Syria was critically important for Turkey's goal of eliminating terrorism at home.