Ambassador Zalmay Khalilzad said that success in Iraq is still possible in a "realistic timetable."
Khalilzad said Iraqi leaders had agreed to a timeline to reduce violence, and that a "national compact" should be in place in the next 12 months if the Iraqi government lives up to agreements.
General George Casey, the top U.S. commander in Iraq, also told reporters that Iraqi forces should be able to take full control of security within the next 12 to 18 months with minimal U.S. support.
Casey said he felt the United States should continue to focus on drawing down the number of American forces in the country, adding that he would not hesitate to ask for more troops if he felt they were necessary.
In Moscow, Russian Foreign Minister Sergei Lavrov said Iraq could break up unless steps are taken to unify the country.
Meanwhile, the leader of Iraq's largest Shi'ite bloc called for the country to be divided into federal zones. According to Abdul Aziz al-Hakim, leader of the Supreme Council for the Islamic Revolution in Iraq, a federal system with only loose central control would prevent the return of dictatorship.
In Iran, Supreme Leader Ayatollah Ali Khamenei called for an end to the bloody sectarian conflict tearing Iraq apart.
(compiled from agency reports)