Swaraj, asked at a news conference whether US action against Iran and Venezuela would damage India, said the country would not make foreign policy "under pressure".
US President Donald Trump this month withdrew from the Iran nuclear deal and ordered the reimposition of sanctions suspended under the 2015 accord.
Washington has also tightened sanctions against Venezuela over the controversial re-election of President Nicolas Maduro.
Both countries are key oil suppliers to India and the United States has warned that foreign companies which deal with Iran could themselves be punished.
But Swaraj said New Delhi did not believe in "reactionary" policies and would not be dictated to by other countries.
"We don't make our foreign policy under pressure from other countries," she told a news conference.
"We believe in UN sanctions but not in country-specific sanctions."
Swaraj's comments came just before a meeting with her Iranian counterpart Mohammad Javad Zarif in New Delhi.
Bilateral trade between India and Iran amounted to $12.9 billion in 2016-17. India imported $10.5 billion worth of goods, mainly crude oil, and exported commodities worth $2.4 billion.
India has other interests in Iran, in particular a commitment to build the port of Chabahar on the Gulf of Oman.
The port is being touted as a way for India to establish trade routes that bypass rival Pakistan.
Media reports have speculated India could revive a rupee-rial payment arrangement with Iran to shield exporters from the heat of US sanctions.
Swaraj also said India would continue trading with Venezuela, but there was no plan to use its local cryptocurrency in oil trade.
"We cannot have any trade in cryptocurrency as it is banned by the Reserve Bank of India. We will see which medium we can use for trade," she said.
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