Ex-Soviet NATO member Lithuania said Thursday it will seek assurances that a planned missile shield will protect all members of the alliance, on the eve of talks with US President Barack Obama.

"During meetings with the presidents of central European states and the president of the United States, we will discuss the strengthening of transatlantic cooperation," Lithuanian President Dalia Grybauskaite said in a statement.

"I will raise issues of urgent importance to Lithuania and other NATO border states. We're seeking that NATO's missile defense system, agreed upon last year in Lisbon, should cover all members of the alliance," she added.

Grybauskaite is one of 20 leaders of ex-communist states due in the Polish capital Warsaw Friday for a summit focusing on two decades of democratic and free market reforms behind the former Iron Curtain.

On the final leg of his European tour, Obama is due to join the summit participants Friday for a working dinner.

Poland and Romania have agreed to host part of a revamped US missile shield to ward off threats from so-called rogue states like Iran.

Current US plans, which fold into NATO missile shield moves reaffirmed at a 2010 alliance summit in the Portuguese capital Lisbon, call for deployment in Romania in 2015 and in Poland by 2018. They have been hotly disputed by Russia, which has dubbed them a security threat.

In Warsaw, Grybauskaite is also due to hold a meeting with the presidents of Lithuania's fellow Baltic states Latvia and Estonia.

The anti-missile plans, and Russia's reactions to them, are particularly high on the Baltic trio's agenda.

The three republics won independence from the crumbling Soviet Union in 1991 after five decades of Kremlin rule, and have rocky relations with their former master.

They joined NATO and the European Union in 2004.

With a total population of 6.5 million and a professional military of 20,500, they see NATO as paramount to their security.