Via AFP:
The United States warned Friday that President Barack Obama and other European leaders could snub the G8 summit in Sochi if they judge Russia is usurping Ukraine's sovereignty.
Obama expressed deep concern at reports that Russian forces had landed in Crimea, following claims by an official in Kiev that an "invasion" was under way.
Senior officials said the president decided to make a surprise appearance in the White House briefing room after Washington concluded that there was evidence that Moscow's forces were indeed active in Ukraine.
Heavily armed troops in uniforms with no nation...
