A Kremlin spokesman quickly rebuked Washington's decision to add the Yuzhno-Kirinskoye Field to its list of energy sector sanctions, saying it "further damaged our bilateral relations."

But spokesman Dmitry Peskov also struck a tone of defiance, denying that American sanctions over Moscow's actions in Ukraine had been effective in weakening Russia's economy.

"The economy is showing its steadiness, so I don't think we can talk about any significant or systematic influence from such actions, which we do not consider successful, legitimate or most importantly far-sighted," Peskov said.

As remote as remote gets

The Yuzhno-Kirinskoye Field is a gas and condensate field located off the far eastern coast of Siberia in the Sea of Okhotsk, near Sakhalin Island.

The state-owned energy giant Gazprom discovered it in 2010 but it isn't scheduled to go into production until 2018.

According to a note in the Federal Register, the daily journal of the US government, the field "is reported to contain substantial reserves of oil in addition to reserves of gas."

'A new arrow in the sanctions quiver'

Specifically, the widened sanctions impose an export ban on items originating in the US and ones in which more than 25 percent of the parts came from the US. If anything were to be exported to the field, an individual or company would need permission from the Commerce Department.

Douglas Jacobson, an international trade lawyer in Washington, speaking to the Reuters news agency, said the new rules represented "a new arrow in the quiver of US sanctions on Russia."

cjc/hg (Reuters, AFP)