North American and European nations of the NATO alliance agreed for the first time to develop a missile defense shield over the next decade to protect against the threat of ballistic missiles for all its member states, President Barack Obama announced on Friday.

The North Atlantic Treaty  Organization, which emerged as a counter-weight to the Soviet Union during the Cold War, is holding a summit for leaders of its 28 member nations and 20 others in Lisbon on Friday and Saturday.

This important step forward builds on the new phased adaptive approach to missile defense that I announced for the United States last year. It offers a role for all of our allies. It responds to the threats of our times, he said.

When it was first presented in 2009, the White House said the phased approach was based on an assessment of an Iranian missile threat and commitment to use proven, cost-effective and adaptable technology. 

The phased-in system would include sea-based interceptors set up in 2011, as well as more advanced sea and land based systems in 2015, 2018 and 2020 to counter short, medium and intermediate range missiles.

Russian President Dmitry Medvedev will be a part of talks on Saturday.

[T]omorrow, we look forward to working with Russia to build our cooperation with them in this area as well, recognizing that we share many of the same threats, he said.

The President also reiterated previous calls for the U.S. lawmakers to ratify the U.S.-Russia START treaty, which would reduce nuclear arsenals by about 30 percent, but would still leave each nation's destructive capabilities unchanged.

Building cooperation with Russia has helped us put pressure on Iran and helped us to equip our mission in Afghanistan, he added.