Experts said the vessels are probably carrying a key precursor for rocket fuel, making it notable that Beijing let them sail while the U.S. and Iran are at war.
Ukraine has claimed a slew of successes on the front line in recent days, underscoring the effectiveness of its weapons systems, including anti-drone interceptors.
President Donald Trump, set to honor slain U.S. service members at Dover, threatened to widen U.S. targets after Iran's president dismissed the notion of surrender.
European leaders are ramping up their response to the crisis spreading outside Iran but remain wary of a conflict that could have untold ramifications.