WASHINGTON – The US has deployed approximately 275 troops “equipped for combat” to Iraq, US President Barack Obama informed Congress on Monday night.The troops are stationed to counter the growing threat of ISIS, a terrorist group threatening the sovereignty of Iraq and Syria.Some 170 US servicemen were deployed over the weekend to protect the expansive US embassy in Baghdad, with 100 more for airfield management, security and logistics support, the Pentagon said.“This action has been directed with my responsibility to protect US citizens both at home and abroad, and in furtherance of US national security and foreign policy interests,” Obama wrote in his notice. “This force will remain in Iraq until the security situation becomes such that it is no longer needed.”The deployment is the first time Obama has ordered troops on the ground in Iraq since commanding a complete withdrawal from that country nearly four years ago.Welcoming home the president from a long weekend in California was his National Security Council, waiting for him at the White House on Monday night. The heads of every US agency involved in military, intelligence and diplomacy came briefed to provide Obama with options on how to counter the ISIS advance.On Wednesday, Obama will host Republican and Democratic Congressional leadership at the White House to discuss those options.ISIS— the Islamic State of Iraq and Syria— has laid siege to much of northern Iraq and has taken control of key cities Tikrit and Mosul.Also on Monday evening, the US acknowledged that, in order to address the dramatic advances of ISIS, a new line of direct communication has been opened with the Islamic Republic of Iran.“The issue did come up briefly with Iran on the margins of the P5+1 in Vienna today, separate from our trilateral meeting,” a senior State Department official said, referring to international negotiation under way over Iran’s nuclear program. “These engagements will not include military coordination or strategic determinations about Iraq’s future over the heads of the Iraqi people.”The contact was “brief,” State Department spokeswoman Jen Psaki said on Monday, and was between US Deputy Secretary of State William Burns and an Iranian official that Psaki declined to identify.“They discussed the need to support inclusivity in Iraq,” Psaki said. “We don’t expect further conversations with Iran on this issue in Vienna.”“It was not the launch of the formal process,” she said.