Ties

This has probably been dealt with before, but I'm in the middle of a game. I had a won game and the opponent successfully whittled my pawns away to a tie (K+R vs K+R). I congratulated him, and assumed we were done. I offered a draw multiple times, but he keeps playing. I guess it's his right to see if one of us makes a mistake but we're both good enough players that it's extremely unlikely.

Suggestions?

He might have missed the draw offer - I did that once because, apparently, it's not that obvious the opponent offers a draw. When you offer a draw also write about that in the chat.

I'm sure 3 years on this advice will come in really handy.

3 fold repitition is the most easiest way to draw the game/