Ukrainian troops have continued to push forward with an offensive that has embarrassed Moscow, as officials in Kyiv and foreign observers hinted at new gains in the southern strategic region of Kherson.

Kherson has been one of the toughest battlefields for the Ukrainians, with progress being slower compared with Ukraine’s offensive around the country’s second largest city of Kharkiv, in the north-east, that began last month.

The Kherson region is one of the four illegally annexed by Moscow last week after a “referendum” orchestrated by the Kremlin. The lower house of the Kremlin-controlled parliament has now ratified the annexation treaties, and the upper house will follow on Tuesday.

Ukrainian media outlets highlighted an image of Ukrainian troops displaying flags at a marker for the village of Khreshchenivka, which is in the same area of Kherson where troops have apparently broken through Russian lines.

Russian military bloggers close to Moscow have increasingly acknowledged that Ukraine has superior manpower, backed by tank units, in the area.

A Russian-installed official in the Kherson region, Kirill Stremousov, admitted in a video statement on Monday morning that the Ukrainian forces “have broken through a little deeper”.

However, he insisted that “everything is under control” and that Russia’s “defence system is working” in the region.

Russia attacked Ukrainian President Vladimir Zelensky’s hometown and other targets on Sunday with suicide drones, and Ukraine took back full control of a strategic eastern city in a counter-offensive that has reshaped the war.

Russia’s recent loss of the eastern city of Lyman, which it had been using as a transport and logistics hub, was a new blow to the Kremlin as it seeks to escalate the war by illegally annexing four regions of Ukraine and heightening threats of nuclear force.

Russian President Vladimir Putin’s land grab has threatened to push the conflict to a dangerous new level. It also prompted Ukraine to formally apply for fast-track Nato membership.

In his nightly address on Sunday, Mr Zelensky discussed the recent liberation of Lyman, a key Russian node for logistics on the front line in the north-east.

“The story of the liberation of Lyman in the Donetsk region has now become the most popular in the media — but the successes of our soldiers are not limited to Lyman,” Mr Zelensky said.

Lyman, which Ukraine recaptured by encircling Russian troops, is in the Donetsk region near the border with Luhansk.

Both are among the four regions that Russia illegally annexed Friday after forcing what was left of the population to vote in referendums at gunpoint.

In his broadcast, Mr Zelensky also thanked troops from his hometown near Kherson.

He also passed on his thanks “to the soldiers of the 129th Brigade of my native Kryvy Rih, who distinguished themselves with good results and liberated, in particular, Arkhanhelske and Myroliubivka”.

Those two villages are in the same area where Ukrainian troops have been making advances. A photo emerged at the weekend showing Ukrainian forces’ operation southwest of Novovorontsovka on the banks of the Dnieper River.

Since the Russian offensive started in February, Ukrainian forces have recently managed to retake swaths of territory, notably in the northeast around Kharkiv, in a counter-offensive in recent weeks that has embarrassed the Kremlin and prompted rare domestic criticism of Putin’s war.