WASHINGTON – Security chiefs from the Arab world will converge on the White House on Wednesday to warn of increasingly “aggressive” Iranian behavior, according to Arab officials.Simultaneously in Vienna, Western and Iranian diplomats will be trying to iron out details of a comprehensive nuclear accord.The two meetings come “at a critical moment in the history of the Middle East,” White House Deputy National Security Adviser for Strategic Communications Ben Rhodes told reporters in a conference call on Monday.“Clearly, there is significant interest in the [Gulf Cooperation Council] about Iran’s destabilizing actions in the region,” Rhodes said, “and this will be an opportunity both to review the status of negotiations with respect to Iran’s nuclear program but also to review our efforts to counter those destabilizing actions in different countries across the region.”Previewing the summit, Saudi Arabian Foreign Minister Adel al-Jubeir said that Iran’s activities would be the focus of the conference, which begins at the White House on Wednesday and moves to Camp David, the president’s Maryland retreat, on Thursday.“The challenge will be in how to coordinate US-Gulf efforts in order to collectively face these aggressive moves on the part of Iran,” Jubeir said, according to state-run news outlet SPA, referring to Tehran’s “support for terrorist organizations.”Senior representatives from all GCC nations – Bahrain, Kuwait, Oman, Qatar, Saudi Arabia and the United Arab Emirates – will be in attendance. Rhodes said the US president’s initial goal is for the leaders to step back and assess the overall state of the region, from Syria to Yemen, Libya to Iran.Jubeir agreed, noting that the wars in Iraq, Syria and Yemen would all be topics of conversation at the summit.But invitations for the event were sent out only after international powers agreed with Iran on a framework agreement capping its nuclear work in Lausanne, Switzerland, last month.That deal, which seeks to monitor, restrict, and partially roll back its nuclear program for a finite period in exchange for sanctions relief, has GCC member states concerned with Tehran’s budding relationship with Washington.The purpose of summit is, in part, for the US to stress “the importance of a comprehensive agreement between the P5+1 [powers] and Iran that verifiably ensures the exclusively peaceful nature of Iran’s nuclear program,” President Barack Obama told King Salman bin Abdulaziz al-Saud of Saudi Arabia in a phone call on Monday.Salman will not attend the summit, nor will the leaders of three of six other GCC nations. But “the right” people, steeped in security matters, will be in attendance at Camp David, Rhodes said.The GCC reportedly seeks advanced weapons systems and contract offers from the US, while the American government seeks agreement on a broad structural defense design that would efficiently coordinate Gulf maritime, counterterrorism, air and anti-missile systems.The Obama administration has long advocated for a missile defense system across the region, the president’s aides point out. The summit is intended to expand the scope of US security guarantees to its Arab allies beyond that single portfolio. In Austria, Wendy Sherman, Washington’s chief negotiator with Iran, arrived with the US delegation for additional talks toward a comprehensive accord.The Lausanne framework attempted to address all core political elements of a final deal, which the parties hope to finish by the end of June.“We hope we can pull together an agreement before July 1,” Abbas Araqchi, Tehran’s chief negotiator, was quoted as saying by Iran’s Mehr news agency as he met European officials in Vienna. “”We have to abide by the solutions and agreements that we reached in Lausanne, and we will only negotiate in that framework.”Diplomats from Russia, China, France, Britain and Germany are due to join their US, EU and Iranian colleagues in Vienna on Friday.Reuters contributed to this report.