The Treaty of Portsmouth was a 1905 international treaty that ended the Russo-Japanese War. It was held at Portsmouth, New Hampshire and presided over by US President Theodore Roosevelt. In this treaty, Russia acknowledged Japan's "predominant political, military, and economic interests in Korea" and both nations agreed to evacuate Manchuria. Both nations continued to maintain a sphere of influence in Manchuria.
Japan would annex Korea in 1910.
The treaty was signed September 5, 1905.