US Secretary of State John Kerry warned Russia that it must not intervene in Ukraine under the "pretext of peacekeeping", his department said.
The statement follows Russia's version of the call, in which its Foreign Minister Sergei Lavrov was said to have called for urgent measures to avert a "humanitarian catastrophe" in the east of the country.
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The business secretary called the move a 'positive step forward' after the US-imposed tariff sparked fears over jobs in Northern Ireland.
A report published by the Boundary Commission for England details plans to reduce the number of MPs by scrapping 50 constituencies.