Russian President Vladimir Putin has suggested that Moscow should try to consolidate its control of four Ukrainian regions it unilaterally annexed last September.

Putin's remarks come five months after Ukraine launched a counteroffensive in its fight against Russia's invasion.

Speaking to a meeting of a government consultative body on Friday, Putin said Russia should work to enable residents of the four regions to feel the benefits of Russian rule.

The regions are Luhansk and Donetsk in the east and Zaporizhzhia and Kherson in the south.

Putin also tried to justify Russia's annexation of the southern Ukrainian region of Crimea nine years ago. He said, "Had our relations with fraternal Ukraine been normal, modern and benevolent, it would have never crossed anybody's mind to take any actions, like those related to Crimea."

Russian forces have been mounting relentless attacks to take the strategically important eastern town of Avdiivka in Donetsk, despite the risk of heavy casualties. On the other hand, Ukrainian troops are continuing their counteroffensive centering on Zaporizhzhia.

The British defense ministry said on Friday that a large-scale Russian assault has foundered due to strong Ukrainian defenses around Avdiivka. It said the Ukrainian advance remains relatively static between the two main lines of Russia's well-prepared defensive positions in the south.

The ministry attributed the stalemate partly to both sides maintaining credible air defenses.

It also cited the geographic size of the conflict. It said both sides have struggled to assemble striking forces capable of breaking through because most of their mobilized troops are needed to hold the 1,200-kilometer line of combat.