President Traian Basescu said the Supreme Defense Council, Romania's top military and security body, had agreed to such a plan after a request by Washington.
"Terrestrial interceptors will be placed on Romania's territory as part of the anti-missile system," Basescu was quoted as saying by Radio Free Europe. "According to the calendar agreed with the American side, the components located on Romania's territory will become operational in 2015."
He said the missile defense system would "protect the whole of Romania's territory" but added that it should not be seen as a threat to former Cold War master Russia.
"It is not against Russia," he vowed.
The announcement came as a surprise. It seems that the stationing of missiles in Romania is part of President Barack Obama's new approach to missile defense, which he had altered in a bid to please Russia.
Moscow had been angry over previous plans tabled by Obama's predecessor George W. Bush to station 10 long-range interceptor missiles in Poland and a radar system in the Czech Republic. The Kremlin even threatened to relocate its own missiles closer to Europe.
Obama's decision to scrap the Bush-era plan came at a time when Washington was trying to reset relations with Russia.
The president's new plan, first unveiled last October when U.S. Vice President Joseph Biden toured Eastern Europe, including Romania, featured a combination of fixed (ground-based) and relocatable (on U.S. warships) Standard Missile 3 interceptors and radars that focuses mainly on the threat from short- and medium-range missiles.
It seems that the ground-based missiles will now be stationed in Romania, a landlocked NATO member in southeastern Europe -- closer to Iran, the reason for the U.S. system, Washington says.
Basescu said the invitation to host the missiles was delivered by U.S. Undersecretary for Arms Control and International Security Ellen Tauscher, Radio Free Europe reports.
The decision has to be approved by Romania's lawmakers to come into effect, but observers say it has good chances to receive a green light as Bucharest has been a close ally for the United States in Europe.