The Belgian, controversially brought in to replace popular boss Chris Powell in early March with the club lying bottom of the table, saw his side secure their survival with a 3-1 win over Watford.
But afterwards Riga, who only agreed a contract until the end of the campaign, brushed aside questions over his future.
"Let me enjoy the present before thinking about it," he said. "The future I have to discuss, I don't know when.
"If you ask me if I enjoy the competition, the club, the fans, then yes. I like England. We have a good foundation here and I think Charlton has a very good future.
"But I know about football, it depends on the situation. It's not a problem. I've done my job and it's enough to be really happy."
Callum Harriott picked the perfect time to score his first league goals of the season.
The rookie winger opened the scoring in the first half with a superb 20-yard strike, and then bettered it with a stunning volley to seal a dramatic win.
There were plenty of nerves around The Valley when Troy Deeney equalised for Watford in the second half with another fine strike for with his 24th goal of the season.
But Charlton captain Johnnie Jackson bundled them back into the lead from Morgan Fox's cross and Harriott got the survival party started with a vicious, curling effort 13 minutes from time.
"Callum has a lot of qualities, he works hard but he needs to learn to control his emotions," Riga added.
"He's a young player and he has learned a lot in the last two months with the situation we are in. Sometimes he makes the wrong choices but he wants to learn. He is always looking to improve so I am happy for him."
The Addicks finished the match with 10 men after Albert Riera flattened Lawrie Wilson for the second time to earn a second yellow card.
Victory meant Charlton were spared the agony of a potential relegation decider at Blackpool on Saturday.
Meanwhile, Watford's season has fizzled out after three straight defeats and unhappy boss Beppe Sannino promptly cancelled his squad's day off on Wednesday.
The Italian also plans to keep them working after Saturday's final game of the season against Huddersfield.
"Because I'm not happy, (on Wednesday) all the squad will be at the training ground because we are professional. We have to work hard to prepare for Saturday," he said.
"The players' contracts run until the end of June so we will keep working after Saturday. We need to build a team for next season with a different DNA.
"We need to have respect for the people watching behind the goal. We must wear the shirt the best way possible, even if we have no targets to achieve."