WASHINGTON - US President Barack Obama discussed developments in Europe and Syria with European leaders earlier Wednesday, the White House said in a statement.

The White House said Obama held a videoconference with German Chancellor Angela Merkel, French President Francois Hollande and Italian Prime Minister Mario Monti. They discussed developments in Europe, following up on the discussions held at the G-8 Camp David Summit and at the informal meeting of European Union Leaders last week.

"Leaders agreed to continue to consult closely as they prepare to meet at the G-20 Summit in Mexico next Month," the statement said.

The Obama administration sent a top economic official to Europe on Tuesday to meet with officials in Greece, Spain, France and Germany to discuss plans for economic stability and growth in Europe. The trip of the Treasury Department's under secretary for international affairs, Lael Brainard, comes as the deepening eurozone crisis provoked concerns over economic prospects of Europe as well as the rest of the world.

The White House said the leaders also discussed recent developments in Syria and their shared perspectives on the importance of ending the violence.

Last Friday's massacre in the central Syrian village of Houla caused deaths of 108 people. Several Westerns countries, including the United States, Canada and Britain, then decided to expel Syrian diplomats, in protest of the killings.

China on Wednesday called for a through investigation into the mass murder of civilians and actions to halt the violence.

Bashar Ja'afari, the permanent representative of Syria to the UN, said Wednesday a national investigation commission in Syria will soon finish its investigation of the events in Houla so that those responsible for the massacre can be identified.

Early Wednesday, the US Treasury added Syria International Islamic Bank to its sanctions list, the latest in Washington's ongoing efforts to try to close off the Syrian government's access to the international financial system.