The former Nobel Peace Prize winner did not go into specifics but Myanmar has seen several deadly outbreaks of violence between Buddhists and Muslims in the last few years amid a surge of Buddhist nationalist sentiment.
This weekend, a movement of ultra-nationalist Buddhist monks is holding a keenly watched conference.
Suu Kyi spoke at the opening of a two-day conference of her National League for Democracy, which is expected to mount a sharp challenge in the polls to the current military-backed government.
"The election is getting closer. I want to stress that stability in the country is very important ahead of elections," said Suu Kyi. "I want to warn that elections could be delayed using instability as a reason."
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Suu Kyi's remarks can be seen as suggesting that the government or the military - which holds power behind the scenes - might want to take advantage of disorder to hold on to power.
Suu Kyi also said when her party contested by-elections in 2012, it pledged to work for amending the 2008 constitution, and it continues to seek that.
The current constitution contains clauses that bar her from becoming president. Parliament this coming week will debate several constitutional amendments.