Russia will deliver missiles capable of carrying nuclear warheads to Belarus in the coming months, President Vladimir Putin has said as he received Belarusian leader Alexander Lukashenko.

“In the coming months, we will transfer to Belarus Iskander-M tactical missile systems, which can use ballistic or cruise missiles, in their conventional and nuclear versions,” Putin said in a broadcast on Russian television at the start of his meeting with Lukashenko in St Petersburg on Saturday.

Putin has several times referred to nuclear weapons since his country launched a military operation in Ukraine on 24 February, in what the west has seen as a warning not to intervene. Lukashenko said last month that his country had bought Iskander nuclear-capable missiles and S-400 anti-aircraft anti-missile systems from Russia.

The development came on the eve of a meeting of G7 leaders in Germany on Sunday, to be hosted by Chancellor Olaf Scholz in the Bavarian alps, which is set to be dominated by Ukraine and its far-reaching consequences, from energy shortages to a food crisis.

The G7 leaders are expected to seek to show a united front on supporting Ukraine for as long as necessary and cranking up pressure on the Kremlin – although they will want to avoid sanctions that could stoke inflation and exacerbate the global cost-of-living crisis.

“The main message from the G7 will be unity and coordination of action … That’s the main message, that even through difficult times … we stick to our alliance,” an EU official said.

The G7 partners are set to agree to ban imports of gold from Russia, a source familiar with the matter told Reuters. A German government source later said that leaders were having “really constructive” conversations on a possible price cap on Russian oil imports.

This year, Scholz invited as partner countries Senegal, the current chair of the African Union, Argentina, which heads the Community of Latin American and Caribbean States, Indonesia and India, the present and next hosts of the G20 group of large industrial nations, and South Africa.

“The summit must send not only the message that Nato and the G7 are more united than ever, but also that the democracies of the world stand together against Putin’s imperialism just as they do in the fight against hunger and poverty,” Scholz told the German parliament this week.

Putin also offered to upgrade Belarus’ warplanes to make them capable of carrying nuclear weapons, amid soaring tensions with the west over Ukraine.

“Many Su-25 [aircraft] are in service with the Belarusian military. They could be upgraded in an appropriate way,” the Russian leader said. “This modernisation should be carried out in aircraft factories in Russia and the training of personnel should start in accordance with this,” he added, after Lukashenko asked him to “adapt” the planes.

“We will agree on how to accomplish this,” Putin said.

During the meeting Lukashenko expressed concern about the “aggressive”, “confrontational” and “repulsive” policies of its neighbours Lithuania and Poland and asked Putin to help Belarus mount a “symmetrical response” to what he said were nuclear-armed flights by Nato near Belarus’ borders. Putin said he saw no need at present for a symmetrical response.

The Iskander-M, a mobile guided missile system codenamed “SS-26 Stone” by Nato, replaced the Soviet Scud missile. Its two guided missiles have a range of up to 500km (300 miles) and can carry conventional or nuclear warheads.

In the past week, Lithuania in particular has infuriated Russia by blocking the transit of goods subject to European sanctions travelling across its territory from Russia, through Belarus, to Russia’s Baltic exclave of Kaliningrad.

Russia has termed it a “blockade”, but Lithuania says it affects only 1% of the normal goods in transit on the route, and that passenger traffic is unaffected.

With Agence France-Presse and Reuters