President Barack Obama and Ukraine Prime Minister ArseniyYartsenyuk will hold consultations Wednesday on Crimea during the countdown to the Sunday referendum on the region’s secession to Russia. Tensions are approaching boiling point as Russian troop movements build up around the peninsula.

In diplomatic moves,  Vladimir Putin talked to Chancellor Angela Merkel, who called the referendum illegal and urged Putin to de-escalate the situation. Chinese President Xi Jinping called Barack Obama as well as Merkel to urge “a political solution” of the dispute and for “all parties to exercise calm and restraint. Last week, Beijing voiced opposition to Western sanctions against Russia - without taking a stand on Crimean secession.