If Washington was to give Kyiv the go-ahead to use the weapons, despite Vladimir Putin’s warning of war, what Russian targets could Ukraine hit? The Independent takes a look below.

The governor of Russia’s Kursk region Alexei Smirnov on Monday ordered the evacuation of residents of all settlements in the province’s Rylsky and Khomutovsky districts situated within 15km (9.3 miles) of the Ukrainian border.

Kursk region has been the scene of bitter fighting since a Ukrainian incursion in early August seized territory along the frontier. Russian troops have in recent days made efforts to push Kyiv’s forces back.

Volodymyr Zelensky says Ukraine’s incursion into Russia’s Kursk region is going “precisely as planned”, as he provided a battlefield update from his commander-in-chief Oleksandr Syrskyi.

“We are defending our positions,” he said, referring to the frontline as a whole, in his nightly video message. “We also reviewed the Kursk operation in detail, and each day we are acting precisely as planned.”

Mr Zelensky said Syrskyi provided details of the slow advance of Russian forces in eastern Ukraine, particularly on the rail and logistic hub of Pokrovsk.

He said 100 battles had occurred in the last 24 hours on the eastern front, with the heaviest fighting gripping the Pokrovsk and Kurakhove sectors.

Capturing Pokrovsk would be a significant step towards Russia’s objective of capturing the whole of the Donetsk region.

Ukraine has asked the United Nations and the International Committee of the Red Cross (ICRC) to join humanitarian efforts in Russia’s Kursk region.

Foreign minister Andrii Sybiha said he had instructed his ministry to formally invite the UN and ICRC to work in the Kursk region when he visited the northeast Ukrainian region of Sumy on Sunday. The ministry confirmed that it had issued the requests.

“Ukraine is ready to facilitate their work and prove its adherence to international humanitarian law,” Sybiha said on X after the visit to Sumy, from where Ukrainian forces launched the cross-border attack.

He said the Ukrainian army was ensuring humanitarian assistance and safe passage to civilians in the Kursk region.

The foreign ministry said in a written statement that the invitations had been issued to the ICRC and UN, “taking into account the humanitarian situation and the need to properly ensure basic human rights in the territory of the Kursk region.”

The ministry said it had asked the ICRC to monitor Ukraine‘s compliance with the principles of international humanitarian law in accordance with the Geneva Conventions, which cover the protection of victims of international armed conflicts.

It was not immediately clear how or whether the UN or ICRC had responded.

Vladimir Putin ordered the regular size of the Russian army to increase by 180,000 troops to 1.5 million in a decree issued yesterday.

This is the third time he has expanded the Russian army’s ranks since sending the military into Ukraine in February 2022.

The overall size of the armed forces will need to be increased to 2.38 million people, of which Putin said 1.5 million should be active servicemen.

In addition, Russia mobilised over 300,000 soldiers in September and October 2022 in an exercise which prompted tens of thousands of draft-age men to flee the country.

The Kremlin has said that no new mobilisation is planned for now, however, and that the idea is to continue to rely on volunteers signing up to fight in Ukraine on lucrative contracts.

Iran’s president Masoud Pezeshkian claims his government has not transferred any weapons to Russia since it took office in August.

Western powers have said they have evidence of Tehran delivering ballistic missiles to Moscow in September for its war in Ukraine, forcing them to impose fresh sanctions on Russia and Iran.

Asked whether Iran had transferred missiles to Russia, Mr Pezeshkian said: “It is possible that a delivery took place in the past… but I can assure you that since I took office, there has not been any such delivery to Russia.”

Reuters reported in February that Iran had provided Russia with a large number of powerful surface-to-surface ballistic missiles, deepening the military cooperation between the two US-sanctioned countries.

Russia and Iran both denied the Western claims.

The outgoing head of Nato Jens Stoltenberg has welcomed talks on Ukraine’s use of long-range missiles to strike inside Russian territory, but any decision on the issue would have to be made by individual allies.

“I welcome these developments and these decisions but it’s for individual allies to make the final decisions,” Mr Stoltenberg told LBC radio. “Allies have different policies on this.”

The decision has been stalled in Washington as some US officials are deeply skeptical that allowing the use of such missiles would make a significant difference in Kyiv’s battle against Russian invaders.

President Vladimir Putin has issued a preemptive threat that the West would be directly fighting Russia if it allowed Ukraine to strike it with Western-made long-range missiles.

Russia says its forces have retaken control of two villages in its western Kursk region from Ukraine, continuing what Moscow says is a significant counter-offensive there.

Russia’s defence ministry said that its troops had retaken the settlements of Uspenovka and Borki. They lie about 12 miles (20 km) apart on the border with Ukraine’s Sumy region.

A senior Russian commander and pro-Kremlin war bloggers said last week that Russia had restored control over about 10 settlements in the region, an assertion that could not be independently confirmed.

Ukraine says its forces control about 100 villages in Kursk over an area of more than 1,300 square km (500 square miles), which Russian sources dispute.

The governor of Kursk region Alexei Smirnov ordered the evacuation of settlements in two districts situated within 15km (9 miles) of the Ukrainian border yesterday.