NATO Secretary-General Jaap de Hoop Scheffer in a statement said the session today in Kabul of the National Assembly was "a visible sign that the democratic process is taking hold" in Afghanistan.
De Hoop Scheffer stressed that NATO peacekeepers will continue to play a "key role" in that respect as the NATO-led International Security Assistance Force (ISAF) expands its operations in the months ahead throughout the country.
The European Union meanwhile called the parliamentary session a "historic occasion."
Both NATO and the EU pledged to continue efforts to help Afghanistan meet its aspirations of peace, security, and democracy.
The inauguration of the assembly was the culmination of a UN-backed plan to bring democracy drawn up after U.S.-led forces overthrew the former Taliban regime in 2001.
Former monarch Mohammad Zaher Shah addressed the inaugural session.
"After long years of war and misfortunes, the Afghan people are gathering once again," said Zaher Shah, whose ouster in 1973 by a cousin marked the start of three painful decades of Afghan history. "The inauguration of this national assembly is the determination and demand of the Afghan people. I want from you -- the representatives of the Afghan people -- unity, national solidarity, and the creation of a prosperous Afghanistan. Do your best." (Click here for a timeline of Afghan history.)
Lawmakers were sworn in by President Hamid Karzai, and the oath-taking ceremony was conducted in the country's official Dari and Pashto languages.
(compiled from RFE/RL's Radio Free Afghanistan and wire reports)