Russia set to annex four Ukrainian regions today

President Vladimir Putin will sign documents today proclaiming Russia's annexation of four Ukrainian regions, as Moscow rushes to lock in territorial claims that the Ukrainian army is threatening to reverse on the battlefield.

The move, one of the legal steps Russia says will lead to formal annexation of 15 percent of Ukraine's territory, confirms that Putin is doubling down on his war against Ukraine despite suffering a major military reversal this month.

The annexation, after what Kyiv and Western countries say were phoney referendums staged at gunpoint on Russian-held Ukrainian territory, has been rejected in the West as an illegal seizure of land captured in war.

Ukrainian President Volodymr Zelensky summoned his security and defence chiefs for an emergency meeting, and promised a robust response to a step he says has killed off chances of reviving peace talks.

The votes "are worthless and do not change reality. The territorial integrity of Ukraine will be restored. And our reaction to recognition of the results by Russia will be very harsh," Zelensky said in a statement.

Washington and the European Union are set to impose additional sanctions on Russia over the annexation plan, and even some of Russia's close traditional allies, such as Serbia and Kazakhstan, say they will not recognise the move.

Putin's annexation ceremony will be held in one of the Kremlin's grandest halls with the pro-Russian figures Moscow considers to be leaders of the four Ukrainian regions -- Kherson, Zaporizhzhia, Donetsk and Luhansk. Russia says the referendums were genuine and showed public support for the move.

After days of speculation over exactly how Russia would mark the annexation, Putin's spokesman Dmitry Peskov confirmed some details of the ceremony yesterday.

Agreements "on the accession of new territories into the Russian Federation" will be signed "with all four territories that held referendums and made corresponding requests to the Russian side," Peskov said.

Putin would deliver a major speech on the subject, he added.

A big concert will be held today on Moscow's Red Square, where giant video screens have already been set up, with billboards proclaiming "Donetsk, Luhansk, Zaporizhzhia, Kherson - Russia!"

With tens of thousands of Russian men fleeing abroad to escape Putin's military call-up, Finland shut one of the few remaining routes to Europe, saying it would no longer let Russians enter by land with EU tourist visas.

Meanwhile, the United States has unveiled another $1.1 billion weapons package for Ukraine that includes 18 High Mobility Artillery Rocket System (HIMARS) launchers, accompanying munitions, various types of counter drone systems and radar systems. The announcement brings the US security aid to $16.2 billion.

Mystery continued to swirl over an apparent attack on the Nord Stream 1 and 2 pipelines under the Baltic Sea, built to carry Russian gas to Europe though already shut.

At least three explosions which sent hundreds of thousands of tonnes of methane gas jetting to the surface this week have left the pipes severely damaged, possibly permanently. Sweden's coast guard said it found a fourth leak.

Western countries have called the incidents sabotage while stopping short of openly ascribing blame. Russia, which has denied involvement, said the incidents looked like acts of state-sponsored terrorism and the United States stood to gain.

Nato said the explosions looked like a reckless and irresponsible act of sabotage, and that any deliberate attack against infrastructure of countries in the Western alliance would be met by a "united and determined response".