Following up on calls by President Trump, Secretary of State Marco Rubio spoke with his counterparts in both countries. But on Sunday morning, skirmishes erupted once more.

Thailand’s Foreign Ministry confirmed Trump’s call with acting Prime Minister Phumtham Wechayachai. “However, Thailand would like to see sincere intention from the Cambodian side,” it said. The ministry reiterated its call for bilateral talks between the two sides.

Cambodia and Thailand each said the other had launched artillery attacks across contested border areas early on Sunday, hours after U.S. President Donald Trump said the leaders of both countries had agreed to work on a ceasefire.