The two diplomats reached the Ukrainian capital by train from Poland on Wednesday.
ADVERTISEMENTUS Secretary of State Antony Blinken and UK Foreign Secretary David Lammy arrived in Kyiv on Wednesday for talks with top Ukrainian officials.
Ukraine has been pressing its allies to allow the use of Western-supplied long-range missiles on targets in Russia, particularly after Blinken accused Iran of providing Moscow with Fath-369 short-range ballistic missiles at a news conference in London.
“We hope that long-range equipment for strikes on the territory of our enemy will be reached and we will have it," Ukrainian PM Denys Shmyhal told Lammy. "We hope for your help and support in this issue.”
“If we are allowed to destroy (Russia's) military targets or weapons ready for attacks on Ukraine, it would certainly bring more safety for our civilians, our people, and our children," Shmyhal also said in a news conference on Tuesday.
The Kremlin said Russia would respond "appropriately" if the US agreed to lift its restrictions on Ukraine using US-supplied missiles to strike targets inside Russia.
"Each decision made by the collective West and then imputed to Ukraine is an additional confirmation that conducting (the war) is justified, necessary and has no alternative," President Vladimir Putin's spokesman Dmitry Peskov said.
Meanwhile, Ukrainian President Volodymyr Zelenskyy unveiled a memorial to the victims of the 1944 Crimean Tatar genocide on Lybidska Square in Kyiv.
Zelenskyy was joined by leaders from Lithuania, Croatia, Latvia, Moldova and the Czech Republic, as well as various government officials and representatives of the Crimean Tatar people.
He emphasised the symbolism of opening a Ukrainian national memorial on the exact spot where a monument to the Cheka — the first Soviet secret police — stood in the past. The monument was dismantled a few years ago.
Three people have been killed and five injured after a Russian strike on the city of Kostiantynivka in Donetsk Oblast on Wednesday, according to the region's governor.
Four houses, a shop, and a power line were also reported as damaged.
It comes as Russia says it captured the Vodiane village in Donetsk Oblast, near Vuhledar, in Ukraine, although this has not been confirmed by Kyiv.
The Russian Defence Ministry claimed to have downed 144 Ukrainian drones which targeted Russian regions overnight. Euronews could not independently confirm these claims.