National Security Adviser John Bolton said Russia is only one of four countries that could potentially try to interfere in the 2018 US midterm elections.

In an exclusive interview with ABC News, Bolton said the US is also concerned about possible election meddling by China, North Korea, and Iran.

“I can say definitively that it’s a sufficient national security concern about Chinese meddling, Iranian meddling, and North Korean meddling that we’re taking steps to try to prevent it,” he said.