US Secretary of State John Kerry arrived in Cairo on Sunday for talks with President Abdel Fattah al-Sisi over Egypt's crackdown on the Muslim Brotherhood and the threat which the conflict in Iraq poses to the Middle East.Kerry is the highest-ranking US official to visit Egypt since Sisi, the former military leader who toppled Islamist President Mohamed Morsi after mass protests last year, won a May presidential election.His visit comes a day after an Egyptian court confirmed death sentences against 183 members of Morsi's Muslim Brotherhood, including its leader Mohamed Badie, in a mass trial on charges of violence in which one policeman was killed.The United States has said it looks forward to working with Sisi's government but also expressed concerns over widespread human rights abuses and limits on freedom of expression."We have serious concerns about the political environment," said a senior State Department official who briefed reporters en route to Cairo.Still, the official said there had been "a few flickering signs of positive movement" in recent weeks. Among these was the release of an Al-Jazeera journalist, steps to start addressing sexual violence against women and Sisi's call during his first cabinet meeting for the revision of the human rights law.The United States, which has counted on Egypt as a close Middle East ally for decades following its 1979 peace treaty with US ally Israel, froze some of the $1.3 billion in annual military aid to Egypt following Morsi's overthrow.About $575 million in suspended funds have been released over the past 10 days and will be used to pay existing defense contracts, the State Department official said.Washington has also said it will provide 10 Apache attack helicopters to help soldiers battling burgeoning militancy in the Sinai peninsula.The Obama administration has made clear that the remaining funds, which require congressional approval, will be released once there is evidence that Sisi's government is ruling in truly democratic fashion, the senior State Department official said.During his meeting in Egypt Kerry will press Sisi to release imprisoned journalists and will raise concerns about the mass trials and death sentences of Muslim Brotherhood supporters, the official said."Those trials are a serious issue of due process concern for us and for others in the international community," the official said, adding: "The judiciary is responding to a political environment that the government has created."The official said the United States did not believe that the Muslim Brotherhood posed a security threat to Egypt and had seen no information that substantiated a link to terrorist groups.The official said the United States had asked Egypt to share the evidence "but at present we do not have that information.""We believe that in a general sense the Egyptian government needs to have a politically inclusive approach, which means that they need to include, and find ways to reach out to, the Muslim Brotherhood," the official said.IRAQ CONFLICTKerry's visit is part of a broader tour of the Middle East and Europe. Obama said on Friday he would dispatch Kerry to the region for talks on the conflict in Iraq.While in Egypt, Kerry will meet members of the Arab League.The official said he would underscore during those talks the severity of the threat posed by Sunni militants to Iraq, the region, and the United States, and the need for Iraqi leaders to form a government not divided along sectarian lines."We ask that they are echoing the same message that we are conveying...that addressing Iraq's security situation is much more likely to be successful in the context of an inclusive government that is formed in short order, and can begin addressing this threat from a solid broad foundation of support," the official said.The Islamic State in Iraq and the Levant (ISIL), an al-Qaida offshoot, has seized swaths of territory in northwest and central Iraq including the city of Mosul. It has taken large amounts of weaponry from fleeing Iraqi troops and looted banks.World powers are deadlocked over the crises in Iraq and Syria. Mainly Shi'ite Iran has said it will not hesitate to protect Shi'ite shrines if asked by Baghdad but Sunni-ruled Saudi Arabia has warned Tehran to stay out of Iraq.Egypt, a mainly Sunni Muslim nation, has the Middle East's largest army but its military forces have played only a limited regional role since they joined a US-led coalition to evict Iraqi forces from Kuwait in 1991.U.S. President Barack Obama has offered up to 300 US special forces advisers to help the Iraqi government recapture territory seized by the Islamic State fighters and other Sunni armed groups across north and west Iraq.But he has held off granting a request for air strikes to protect the government and renewed a call for Iraq's long-serving Shi'ite prime minister, Nuri al-Maliki, to do more to overcome sectarian divisions that have fueled resentment among the Sunni minority.