Alexander Hug told reporters in Kiev that the results of the visit will be available in the mission’s daily report to be published in the coming hours.
On May 16, Kiev detained two Russian nationals during clashes in the Donbass region. The two men were wounded and then captured by Ukrainian law enforcement officers.
The Russian Defense Ministry said Monday that the detained are Russian citizens, but are not serving in the Russian Armed Forces.
The Russian Embassy in Kiev demanded a meeting of consular officials with two Russian nationals recently detained in eastern Ukraine's Lugansk region to provide them with urgent medical aid, the Russian Foreign Ministry said on Tuesday.
Ukraine and its Western allies have repeatedly accused Moscow of sending its regular troops and providing military equipment to independence supporters in Donbass. The claims have not been independently verified. Russia has refuted the allegations, although it admitted that some of its citizens were traveling to Ukraine on a voluntary basis to fight alongside pro-independence militias.