British Prime Minister Andy Burnham hit back at Russian threats Tuesday by saying the U.K. would continue to "support Ukraine 100%."

Russia accused the U.K. of deliberately escalating the conflict and said the deeper the country's involvement became, "the higher the price it will pay."

During a visit to Wolverhampton bus station, Burnham was asked what his message to Russian President Vladimir Putin was in response.

He said: "This is the U.K. doing what it has long said it would do, which is to support Ukraine 100% against this illegal war led by Vladimir Putin."

"We are providing support so that Ukraine can defend itself, and that’s been the British position all the way through this conflict by previous prime ministers. It remains the case with me."

"We are not fair-weather friends. We will be there in Ukraine’s hour of need, and that won’t change."

Ukraine used drones made by two U.K. companies as part of a so-called deep strike campaign, the Sunday Times reported.

Kyiv has stepped up its attacks on Russia this year, with long-range missiles and swarms of drones increasingly targeting military industries and energy facilities.

It has also targeted giant depots for Wildberries – Russia’s largest online retailer – burning merchandise and bringing the war home to the Russian public more than four years into Moscow’s full-scale invasion of Ukraine.

Russia’s embassy to the U.K. said in a statement Monday that the reports "confirm that London is deliberately opting for an escalation of the Ukraine crisis" and accused Britain of "seeking to contain Russia and inflict maximum damage on it by proxy."

"London’s actions will inevitably carry consequences for which it will have to answer," it added.

"The deeper its involvement in the conflict and the greater its support for Kyiv’s terrorist machinery, the higher the price it will pay."

A Defense Ministry spokesperson said: "Britain stands shoulder to shoulder with Ukraine and we are committed to providing the equipment Ukraine needs to defend itself against Putin’s illegal invasion."

"Russia should be in no doubt about the resolve of this government to stand against Russian aggression, in Ukraine and against the U.K. and our allies."

Ukraine’s strategy of long-range drone strikes is believed to be aimed at cutting Moscow’s revenue for the war and making Russian citizens feel the impact of the invasion.

It launched three times as many of those strikes in July as it did in January, according to data from ACLED, an independent conflict monitor.

Repeatedly hitting deep into Russia has forced its military to stretch air defenses over a larger area.