The US supports the \'\'peaceful, legal transition to a democratic regime\'\' underway in Egypt, and it appreciates Egyptian declarations on the importance of respecting international treaties, US Defense Secretary Leon Panetta said at his meeting with Egyptian President Mohamed Morsi on Tuesday. The leaders discussed security issues, particularly \'\'the increase in extremism along Egyptian borders,\'\' especially in the Sinai on the border with Israel, MENA news agency reported. Panetta, who also met with Military Council Chief Hussein Tantawi, said the talks were \'\'constructive.\'\' The US defense chief also highlighted the importance of \'\'strong\'\' US-Egyptian military relations, calling them \'\'an axis of regional stability for 30 years,\'\' MENA said. Egypt still faces many challenges, such as creating democratic institutions, constitutional and economic reforms, and re-establishing security, Panetta said. Meanwhile, Egyptian President Mohammed Morsi wrote to President Shimon Peres a brief letter, Haaretz daily reported on Tuesday. The leader stated that Egypt is committed to regional security and stability, including for the Israeli people, \"I will make the most intense efforts to put the Middle East peace process back on the right track, in order to ensure safety and stability for all the peoples of the region, including Israel,\" Morsi wrote, in what was his first missive to the Israeli government since taking office in June. The letter was sent in response to two messages of congratulations from Peres, one for Morsìs election, the other for the beginning of the Ramadan holy month.