(OilPrice) Russian President Vladimir Putin has responded to U.S. and EU sanctions by warning that further action against Russia could force him to reconsider the involvement of western oil companies in his country.

If the West issues another round of sanctions, “then of course we will have to consider who’s working and how in the Russian Federation, in the key sectors of the Russian economy, including energy,” Putin told reporters in Belarus on April 29. “We really don’t want to take these reciprocal steps.”

The not-so-veiled threat increased uncertainty for the billion dollar investments held by several major oil companies, including ExxonMobil, BP and Royal Dutch Shell.

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