Merkel, among the key players in efforts to ease the euro zone's debt crisis, offered her own congratulations for the US Senate's passage this week of a Wall Street reform bill that Obama has pushed as one of his top domestic priorities.

"They discussed the importance of coordination on regulatory matters and renewed growth in the run up to the G-20 (summit) next month in Canada," the White House said in a statement.

The two leaders also talked about "ongoing coordination on the international community's concerns regarding Iran's nuclear program," the White House said.

Washington and Berlin are involved in efforts to secure new UN sanctions against Tehran. Western powers accuse Iran of trying to develop nuclear weapons. Iran says it only wants nuclear technology for civilian electricity generation.