NATO foreign ministers will discuss the Alliance's capabilities in Eastern Europe and its relations with Russia in Brussels on Tuesday, and are expected to endorse NATO's increased air, sea and land presence for the next year.
"I expect to see (...) an agreement on continuous NATO presence in the eastern part of our Alliance next year," NATO Secretary General Jens Stoltenberg told reporters on the eve of the meeting.
US Ambassador to NATO Douglas E. Lute said the assurance measures were "designed to emphasize and demonstrate that Article 5 of the North Atlantic Treaty that an attack on one is an attack on all means what is says".
In response to Russia's annexation of Crimea and the ongoing war in eastern Ukraine, NATO sent additional fighter jets to Lithuania and Estonia earlier this year and stepped up patrol in the Baltic Sea while company-sized contingents of US troops were deployed in each of the three Baltic states and Poland.
During the summit in Wales in early September, NATO also announced plans to create the so-called "Very High Readiness Joint Task Force", and Lithuania said it would seek preposition of equipment and establishment of an international headquarters directly accountable to NATO command.
Diplomats say the implementation of such plans could take some time due to limited resources and a lack of strong political will.
Germany, the Netherlands and Norway plan to from the interim "spearhead" force next year but the ongoing discussions are now focused on the number of days, not hours, the new force would have to get ready to strike the first blow to an aggressor.
Under the plan, the new force of around 4,000 troops would start fully functioning by the NATO summit in Warsaw in 2016.
The formation of the new force is also related to the potential preposition of equipment and the creation of international military headquarters, called "command and control elements", in the Baltic states, Poland and Romania.
The issue might be touched upon during the meeting of NATO foreign ministers but specific decisions are expected next year at the earliest, diplomats say.
On the eve of the meeting, Russia said that by bolstering its capabilities, NATO is destabilizing the situation in Northern Europe. The United States rejected the accusation, saying that the security situation in Europe is being destabilized by Russia's aggression in Ukraine and "irresponsible" flights of military aircraft along NATO's borders.
NATO's relations with Ukraine, the new mission in Afghanistan and fighting the Islamic State group will be also discussed by NATO foreign ministers during the two-day meeting in Brussels.