KIEV, April 15 - Russian President Dmitry Medvedev may pay a visit to Ukraine on April 21 for talks with Ukrainian counterpart Viktor Yanukovych, a source at the Yanukovych administration said Thursday.

This will be the fourth meeting between the two leaders since March 5 as Ukraine has been seeking to persuade Russia to lower natural gas prices. Medvedev is also scheduled to visit Kiev on May 17.