i Register
In some senses, cheerleader is marked as figuratively, US. Watch for register when choosing this word.
noun
A person, usually a young, attractive female, who encourages applause and cheers at a sports event, and wearing a specially-designed uniform in the official colors of the team he/she cheers for.
A person who rallies support for any cause.
Given these sentiments, it is unsurprising that ultranationalists have been the main cheerleaders of closer Russia-North Korea relations.