World Economic Forum recently identified spread of disinformation as the most serious short-term global risk and one of the biggest challenges democratic countries around the world had to ever face. It is therefore essential to search for and test interventions capable of mitigating the negative effects of disinformation. In one laboratory (N1 = 220) and two (N2 = 476, N3 = 655) online experiments utilizing a Pretest-Posttest design, we measure trust in true, false and disinformation statements related to Russo-Ukrainian war and examine the effects of refuting disinformation statements with factual information. By manipulating the timing of the factual information, we test whether it is more effective to refute disinformation after an individual was already exposed to it (i.e., to debunk) or to intervene before disinformation exposure (i.e., to prebunk). Across our three experiments, we consistently find that while Debunk intervention significantly reduces the trust in disinformation and the effect lasts for at least a couple of weeks, Prebunk intervention is effective only (i) for a very limited period of time or (ii) if it is applied just moments before exposure to disinformation.