Somalia Progress: US Official Visits Mogadishu The highest ranking U.S. official to visit Somalia's capital in nearly two decades landed in Mogadishu on Sunday in another sign of improving security in the Horn of Africa's most chaotic nation. Johnnie Carson, the assistant secretary of state for African affairs, arrived at the seaside airport Sunday morning, where he met with the Somalia's president and prime minister. The U.N.'s top official visited in December - the first visit by the U.N. secretary general in nearly two decades. At a news conference in neighboring Kenya after the trip, Carson said he traveled to Mogadishu to acknowledge the "significant progress" made in the capital, especially over the last year, but he was also there to meet with government officials and urge them to make sure the political work on the constitution and upcoming elections are completed. A new constitution and government are supposed to be in place on or before Aug. 20, when the U.N. mandate for the current transitional government expires. The international community is pressing Somali leaders to finish that work. "There has been substantial progress made on the security front in Mogadishu and the environs," Carson said. "A lot of this is the credit and work of" African Union troops. Carson did not leave the airport compound, which is secured by Ugandan and Burundian troops, a sign that U.S. security officials did not believe that driving through Mogadishu's streets - where al-Shabab can still launch insurgent attacks - was safe. The upcoming political transition was one of the main reasons behind Carson's visit. Carson noted that eight or nine diplomatic missions now have personnel in Mogadishu on a full- or part-time basis, but he did not say the U.S. had any plans to reopen an embassy in Somalia. "We will in Washington continue to assess the security situation and when we believe it is both appropriate and safe we will consider stationing officials there," Carson said. But I underscore that things are moving in a very positive direction there. We want to encourage that continued forward progress. AP reporter Jason Straziuso in Nairobi, Kenya, contributed to this report.