Original:  Yushchenko issued an official call to speed up the closure of the Chernobyl atomic power plants on July , 20. Immediately after he left the country with his family for an unofficial visit to Poland, that will be followed by an official visit to Germany.
Revised:  Yushchenko issued an official call to speed up the closure of the Chernobyl atomic power plants on July , 20. Immediately after he left the country with his family for an unofficial visit to Poland, which will be followed by an official visit to Germany.
Edit intent: fluency