Putin casts doubt over Ukraine grain deal and gas for Europe

President Vladimir Putin mooted on Wednesday reopening a U.N.-brokered deal for Ukrainian grain exports via the Black Sea and threatened to halt all energy supplies to Europe if Brussels caps the price of Russian gas.

In a combative speech to an economic forum in Russia's Far East region, Putin also said that Russia would not lose its war in Ukraine and had strengthened its sovereignty.

Ukraine remained guarded about its counter offensive in the east but warned that Russia could turn to nuclear weapons and other nations could be drawn into a protracted "Third World War."