VIENNA -- After the United Nations Security Council agreed to a press statement on Saturday calling for a ceasefire between Israel and Hamas, the foreign ministers of its five permanent members— the United States, United Kingdom, France, Russia and China— gathered in Vienna on Sunday expecting to discuss the crisis. The United States is growing "concerned about escalating tensions on the ground" in Gaza, US Secretary of State John Kerry told Prime Minister Benyamin Netanyahu by phone on Sunday, as Operation Protective Edge entered its seventh night. "He described his engagement with leaders in the region to help to stop the rocket fire so calm can be restored and civilian casualties prevented, and underscored the United States' readiness to facilitate a cessation of hostilities, including a return to the November 2012 ceasefire agreement," one senior State Department official said.Kerry did, however, restate the Obama administration's condemnation of rocket attacks from Gaza against Israel's citizens, and repeated American support for Israel's right to defend itself.In Vienna, at the Palais Coburg, entering meetings with his counterparts, French foreign minister Laurent Fabius said that securing a ceasefire was an "absolute priority" for Paris."There are large numbers of victims in Gaza and rockets have been fired at Israel, and with an absolutely disastrous escalation, France— like the United Nations Security Council— asks for a return to the agreement of 2012," Fabius said, declining to assign culpability when pressed by journalists.The world's top diplomats have gathered in Austria to determine whether a deal with Iran over its nuclear program is possible to forge in the next week. The deadline for those talks is July 20.One senior US official told journalists on Saturday evening that the Obama administration considers Iran partially at fault in the Gaza crisis— and that Kerry would make that clear to his Iranian counterpart, Javad Zarif, in a rare one-on-one meeting planned for Sunday afternoon.The two men have met only once before since rapprochement began between the two nations last September."Iran has a longstanding record of supplying weapons, rockets, to various terror groups in Gaza, including Hamas," the US official said from Vienna. "Those rockets are being used to fire at civilian areas, and Iran has a responsibility to cease and desist from continuing to supply weapons in this conflict."The conflation of these crises is not lost on diplomats gathered in the Austrian capital, distracted by a new global crisis nearly every month since the talks began: from the annexation of the Crimea region of Ukraine by Russia, to advances by ISIS through Syria and Iraq.Nevertheless, a comprehensive nuclear deal with Iran remains the priority of this gathering, another US official insisted, noting that whenever foreign ministers are together, "they discuss whatever is happening in the news and in the day."