Thailand's military said on Monday that it has stopped fuel shipments passing through a border checkpoint with Laos because of fears they were being diverted to Cambodia, with which it is fighting a fierce border conflict.

Trump announced the agreement to restart the ceasefire in a social media posting on Friday following calls with Thai Prime Minister Anutin Charnvirakul and Cambodian Prime Minister Hun Manet.

Escalating border fighting has shut down over 2,000 schools across Thailand and Cambodia, affecting 216,000 students. Experts warn of a lost generation as 600,000 are displaced by the conflict.

BANGKOK, Dec 14 (Reuters) - Thailand's military said it was considering blocking fuel exports to Cambodia, as fighting between the two countries spread to coastal areas of a disputed border region two days after U.S. President Donald Trump said the sides had agreed to a new ceasefire.

Fighting has flared up several times this year since a Cambodian soldier was killed in a May skirmish, as decades-old tensions over the border territory persist.

The escalation broke the ceasefire brokered in July by Trump who threatened to halt trade talks with the two countries unless they ended the fight.