Gonchar's international career began in the late 1990s when he first played for the Russian national team. He made his mark on the international stage during the 1998 Olympics, helping Russia earn a silver medal. At the 2002 Winter Olympics in Salt Lake City, where he helped lead Russia to a bronze medal. His impressive performance earned him a spot on the tournament's All-Star Team as the best defenseman.
In subsequent years, Gonchar continued to represent Russia in various tournaments, including two World Cups of Hockey and multiple IIHF World Championships. He won three bronze medals at the World Championships in 2002, 2005, and 2007. Additionally, he played a key role in Russia's victory at the 2008 IIHF World Championship, where he contributed offensively and displayed his exceptional defensive skills.
One of the highlights of Gonchar's international career came in 2010 at the Winter Olympics in Vancouver. He was a vital part of the Russian team that reached the quarterfinals but was ultimately eliminated by Canada, who went on to win the gold medal. Despite the team's early exit, Gonchar's experience and leadership were highly regarded. It was Gonchar's fourth Olympic Games, and, knowing his career was winding down, a tournament he cherished greatly.