A senior Iranian official told Al Jazeera: A delegation from Qatar arrived in Tehran today to conduct negotiations as part of mediation efforts aimed at ensuring regional security and stability. The Qatari delegation's visit is part of the ongoing consultation between the two countries against the backdrop of growing regional tensions. The obstacle to achieving a diplomatic solution is not the mediation process itself, but the rejection of our legitimate demands by Washington. Mediation efforts are positive, but they always face a violation of commitments by the US government.