President Trump’s administration has maintained a direct backchannel to the North Korean regime over the last several months, even as the two countries continue to spar in public, according to a new report.

Diplomats from each country maintain a relationship with each other in New York, fostered as well by outside groups that favor direct engagement. The revelation comes as the United States and North Korea have engaged in a war of words over sanctions that are designed to induce the North Koreans agree to dismantle their nuclear weapons program as a condition of negotiations with the west.