U.S. President Barack Obama on Friday afternoon spoke separately with French President Nicolas Sarkozy and German Chancellor Angela Merkel on the latest developments in the eurozone crisis, the White House said in a statement.

"Noting the significant steps taken at the July 21 summit of leaders of the euro area and the importance of their implementation," Obama welcomed "the continued leadership" of Sarkozy and Merkel in addressing the challenges facing Europe's economy, said the statement.

The calls came after financial markets around the globe took a nose-dive on Thursday amid fears about Europe's ability to tackle its debt crisis and a global economic slowdown.

The leaders also condemned Syria's "continued use of indiscriminate violence" against its people, welcoming Wednesday's UN presidential statement condemning Syria's actions.

They also agreed to consider "additional steps to pressure the Assad regime and support the Syrian people," according to the statement.

The EU decided to extend sanctions against Syria on Monday, imposing asset freezes and travel bans on five more Syrian officials.

U.S. State Department spokesman Mark Toner said on Thursday that the U.S. was weighing additional sanctions to increase "both political and financial pressure" on the Syrian government, in order to "put a squeeze on his regime."