Fighting between Thailand and Cambodia entered its fourth day on Thursday as both sides waited for a promised telephone call from U.S. President Donald Trump, who says he believes he can again end the conflict between the two Southeast Asian nations.

The US State Department announced that 85,000 visas have been revoked since January, underscoring the Trump administration’s intensified focus on immigration enforcement and border security.

Both countries have said they have evacuated hundreds of thousands of people from border areas.