Signs that North Korea is making preparations for a visit by Russian President Vladimir Putin as early as this week were confirmed at a Pyongyang airport, with planes completely cleared from the tarmac, according to a report Wednesday based on satellite imagery. NK News, a website that provides news and analysis on North Korea, said the removal of planes is rare and normally associated with visits by a foreign leader, but it could be intended to “make room for Putin’s advance team.” The Russian leader plans to visit North Korea and Vietnam in the next few weeks, Russian newspaper Vedomosti rep…