Bloomberg reported that U.S. stocks fell, with the S&P’s 500 Index extending its steepest weekly drop since March, as Greece scrambled to avoid a cash crunch.

Bloomberg said the onus is on Greece to act quickly to avoid a meltdown of its banks, which the government now says will remain closed through Wednesday.

The uncertainty in Greece overshadowed U.S. economic data that, while improving, wasn’t strong enough to boost prospects for an increase in Fed interest rates, Bloomberg noted.

Access the full Bloomberg report on financial crisis in Greece here.