Oksana Markarova, Ukraine's ambassador to the United States, said that since the end of May, Washington has "changed its tone", commenting on the possible transfer of long-range ATACMS missiles to Kyiv.

"If before all the answers sounded like 'Just forget it', then now for the first time we heard that the issue is being discussed," Markarova said in an interview with The Page.

According to the ambassador, negotiations between the American and Ukrainian parties, which concern political and military issues, are usually non-public.

"But there are no insurmountable red lines, and there are many possibilities about which we first heard 'no' and then heard 'yes'.  It's not always because there was a clear ‘no’ position and it changed to a clear ‘yes’ position – it's because there is a large set of factors involved in getting each opportunity. And the political readiness to provide assistance is an important, but far from the only, factor," Markarova emphasised.

She added that in the issue of arms transfer, the US considers a number of factors at once, including availability, training and supply, integration with weapons systems already available in Ukraine, availability of weapons in sufficient quantity, finding such a capability not only in the US, but also in other partners, the manufacturing complex that has to support this, and the logistics.

ATACMS are surface-to-surface missiles that can fly about 300 kilometres, roughly four times the range of the missiles used by the mobile HIMARS systems that the US began providing to Ukraine last year.

Previously, the media reported that the Biden administration explains its reluctance to transfer longer-range ATACMS missiles to the Ukrainian side by the fact that in this case there may be too few of them left in the reserves of the American army.

Last week, the US Congress introduced a resolution calling on President Joe Biden's administration to hand over ATACMS long-range missiles to Ukraine.