"[The] fact that Somalia's institutions have weathered several storms in the last months gives me confidence that our hopes are not misplaced," Kay said in a Tuesday briefing to the U.N. Security Council by video link from Mogadishu.
Somali Prime Minister Abdi Farah Shirdon lost a vote of confidence in the Somali Parliament 184-65 after 15 months in office.
Kay said the vote was a testament of the strength of Somalia's fledgling political institutions.
Somalia last year formed its first functioning central government in more than 20 years. The government in Mogadishu is tested by terrorism and separatist claims.
Kay last month said political violence in the northern Somali region of Puntland was a sign of Somalia's enduring challenges.
"Somalia will be a stable partner in the region and the world when it has strong state institutions, including accountable and professional national security forces," he told the Security Council.
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