In tweets, Swaraj also said that she was back from New York and would be travelling to poll-bound Bihar tomomrrow.
"Thank you Prime Minister for your words of inspiration," she tweeted.
Modi had yesterday praised Swaraj for "wonderfully" highlighting India's contribution to the UN during her speech at the UN General Assembly.
"Just spoke to @SushmaSwaraj ji & congratulated her for the excellent speech at the @UN. A perfect articulation of key global issues," Modi had said in a tweet.
"Back from New York. I'm in Bihar tomorrow," Swaraj said in another tweet today.