The leaders of both Russia and Ukraine are showing no signs of conceding ahead of next month's second anniversary of the start of Russia's invasion.

Russian President Vladimir Putin said on Tuesday that it is obvious that the initiative is completely in the hands of Russian forces.

Ukrainian President Volodymyr Zelenskyy said in a speech at the World Economic Forum in Davos on Tuesday that the war must end "with a just and stable peace."

An analysis by the British defense ministry on Wednesday referred to Ukraine's announcement on Monday that its air force had shot down a Russian early warning and control aircraft over the Sea of Azov.

The ministry said the possible successful targeting of the aircraft by Ukraine is "significant," adding that it "is likely that Russia will now be forced to reconsider limiting the operational areas of its aircraft."

Meanwhile, fighting on the ground is believed to be at a deadlock. The Ukrainian military is facing a shortage of ammunition as support from the West has been held up.

Reuters news agency quoted a member of a Ukrainian unit near Bakhmut in the eastern province of Donetsk as saying, "In order to advance, to move the front line, we need ammunition, we need more man power, we need weapons."