Trump co-signed a truce between the two countries on Oct 26 during a tour of Asia, touting it as one of several peace deals around the world that he believes should win him the Nobel Prize.

But Thailand suspended the deal on Monday after a landmine blast, and the two sides traded accusations of new clashes on Wednesday in which Phnom Penh said a civilian was killed.

“President Trump held calls with Thailand and Cambodia in an effort to mediate the most recent conflict,” the White House said in a statement.

“He engaged with Malaysia as well to help end the violence.”

Malaysia has been acting as a broker in ending the conflict and Trump co-signed the deal in Kuala Lumpur.

Five days of combat erupted between Thailand and Cambodia this summer, killing 43 people and displacing around 300,000 before the truce took effect.

Thailand and Cambodia have a dispute over parts of their border dating back more than a century, but July’s fighting was sparked by Thailand’s claims that Cambodia planted landmines that wounded its troops.