"Everyone is aware of the extreme conditions at Siachen. Overcoming every challenge our soldiers stand firm, protecting our motherland," Modi said in a tweet.
"Be it the altitude or bitter cold, nothing deters our soldiers. They stand there, serving our nation. They make us truly proud.
"Am going to Siachen with a message from each and every Indian to our soldiers: that we stand shoulder to shoulder with you," he said in tweets from his personal Twitter account.
Siachen glacier is the world's highest battlefield at a height of 5,400 meters. Its ownership is disputed by Pakistan.
Modi will visit Srinagar from Siachen to meet victims of the recent unprecedented floods that ravaged the Kashmir Valley and the Jammu region.