Ukraine has asked Russia to repatriate several high-profile prisoners, raising hopes for an exchange that could free controversial detainees caught up in the confrontation between the two countries. The two countries are separately considering appeals from thirteen Russians jailed in Ukraine to serve out their sentences in their home country. The ministry said it would take thirty days to consider the Ukrainian request, and that any repatriation would be carried out under the 1983 convention on the transfer of sentenced prisoners. Four Ukrainian men were jailed in Russia last year on what critics say were fabricated charges of terrorism designed to punish them for being pro-Ukrainian activists.