Former US national security adviser John Bolton described US sanctions targeting Iran’s oil exports as a major success and said they should remain in force. In an interview with the US television network NewsNation, he said the restrictions had been highly effective in preventing Iran from exporting oil and other goods and were having a significant effect on Iran’s economy.

Bolton identified China as the biggest challenge to US pressure on Iran. He said China has long been among the principal buyers of Iranian oil and claimed that Iran has been able to move financial resources through China’s banking system. He argued that Washington should focus primarily on countries helping Iran sustain itself.

He suggested that the United States could impose sanctions on Chinese banks and state institutions involved in purchasing Iranian oil. Bolton also supported applying additional financial pressure on Iran, but said maintaining the oil blockade was the most important measure. He said keeping the restrictions in place would represent major progress and would have a substantial economic impact on Iran.