"It is completely unacceptable that Swedish citizens are travelling to (join) IS, financing the organisation, or fighting for it," Justice Minister Morgan Johansson and Interior Minister Anders Ygeman wrote in a joint article in leading newspaper Dagens Nyheter.
The proposed ban would prohibit combat for terrorist organisations listed as such by the United Nations or European Union.
"We have a responsibility for what our citizens do both here at home and in other countries," they wrote.
Johansson told reporters at a press conference that he had commissioned a report on the possibility of introducing such legislation, which was to be submitted to the government in June 2016.
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In a bid to stem the flow of foreign jihadists, the UN Security Council adopted a resolution last year requiring member states to adopt laws making it illegal to travel or make plans to travel to a country to join jihadist groups, or to collect funds for recruitment.
A government-commissioned report has proposed a maximum two-year prison sentence for those crimes.
Swedish intelligence service Sapo has said that about 150 people from Sweden are known to have travelled to Syria and Iraq to join Islamic militant groups, but that the figure may be as high as 300.