The NATO Response Force (NRF) is a high-readiness force comprising land, air, sea and special forces units capable of being deployed quickly. Until February 2022, when NATO activated it in response to Russia's invasion of Ukraine, units assigned to the NRF had only been used to assist with disaster relief and security at high-profile security events. On 25 February 2022 after a NATO meeting, the Very High Readiness Joint Task Force (VJTF) was activated for the defense of members of the alliance, for the first time. Rotating forces through the NRF requires nations to meet the demanding standards needed for collective defence and expeditionary operations. As the standards are very high, participation in the NRF is preceded by a six-month NATO exercise program in order to integrate and standardize the various national contingents. Generally, nations carry out a pre-training period in preparation for the NATO exercises of between 6–18 months. Once activated, Reconnaissance Teams deploy within 5 days. This is the first of a number of deployment phases that lead to the deployment of the entire HQ Joint Task Force and Immediate Reaction Forces within 30 days. The NRF currently comprises up to 40,000 troops and will be increased to over 300,000 troops. It includes units from several countries that do not belong to NATO: non-member partners, Finland, which first contributed forces in 2008; Sweden, 2013; Ukraine, 2014; and Georgia, 2015. The NRF trains for various tasks, including: providing immediate collective defence of Alliance members in the event of an Article V operation; crisis management; acting as the initial force deployment as a precursor to deployment of a much larger force; peace support; disaster relief; protection of critical infrastructure. Structure The NRF structure consists of four parts: Command and Control element: based on a deployable Joint Task Force HQ Very High Readiness Joint Task Force (VJTF) Initial Follow On Forces Group: These are high-readiness forces that can deploy quickly following the VJTF, in response to a crisis Response Forces Pool: NATO retains a broad spectrum of military capabilities encompassing command and control, combat and support units through the Responses Forces Pool (RFP). The forces are drawn from the much wider pool of Allied or Partners National deployable forces. History Creation and early years The NRF concept was first endorsed with a declaration of NATO's Heads of State at the Prague Summit on 22 November 2002 and approved by NATO Defence