European Commission chief Jean-Claude Juncker warned Greece's new government that Brussels will not change all of its rules just to solve the debt crisis in Athens.
Greece will not deliver a strong economic recovery unless authorities loosen austerity programs, US President Barack Obama suggested in remarks that aired.
Greek Finance Minister Yanis Varoufakis said he wanted to reach a new agreement with international creditors on his country's debt burden "by the end of May".
German Chancellor rejected the prospect of debt relief for Athens, adding to tensions between the radical new Greek government and its international creditors.
French Prime Minister Manuel Valls sought to reassure Chinese concerns about the eurozone, insisting that Greece will stay part of the single currency.
The White House said it was "monitoring closely" events in Greece, where a new hard-left government has vowed to reopen the terms of a massive financial bailout.
The White House said it hoped to work closely with Greece's new government after the radical left-wing Syriza party stormed to power on an anti-austerity platform.