By Ian Talley 

WASHINGTON--The White House on Monday called on Greece to deliver on its previous commitments to overhaul its economy, but said Athens' creditors must also ensure the country's debt is sustainable to reach a deal that keeps the nation in the eurozone.

"It will require both a package of financing and reforms that will allow Greece to achieve, or at least be on a path towards some debt sustainability," White House press secretary Josh Earnest said.

"But it is also important for Greece to implement the kinds of reforms and to keep the commitments that they've made previously," he said.

The White House comments follow an emphatic rejection of Greece's creditors' bailout terms on Sunday by the country's voters. They are also at odds with Germany's position as the eurozone's fiscal hawk opposing debt relief.

Mr. Earnest also played down the potential impact of the Greek crisis on the U.S., saying the U.S. has little direct exposure to the country. Still, he warned that if Greece's woes weighed on the eurozone's economy, it could damp U.S. exports.

The White House spokesman declined to say whether the U.S. would press the eurozone to restructure Greece's debt. But the International Monetary Fund has said that Greece's debt will be unsustainable without debt relief, including extending the country's debt maturity by 20 years "at a minimum."

Write to Ian Talley at ian.talley@wsj.com