The 100 fresh sanctions, announced on Friday, target Moscow’s military and energy sectors, the Foreign Office said.
Ms Cooper arrived in Kyiv on Friday morning, where she was met by Ukrainian foreign minister Andrii Sybiha at a railway station in the city.
The trip, which comes after Russian drones violating Polish airspace during attacks on Ukraine were shot down by Poland and Nato this week, is intended to signal the UK’s steadfast support for the war-torn nation.
Announcing the new sanctions, Ms Cooper said: “The UK will not stand idly by as (Russian leader Vladimir) Putin continues his barbaric invasion of Ukraine. His complete disregard for sovereignty has been shown this week when he recklessly sent drones into Nato airspace.
“International action to increase economic pressure on Russia and to cut off critical cash flows, which he desperately needs to pay for this illegal war, is vital.
“These sanctions form the next stage in the UK’s leading efforts to ramp up economic pressure, alongside our security support and our work alongside the Coalition of the Willing for a just and lasting peace in Ukraine.”
Among the companies sanctioned are firms which supply Russia with equipment such as electronics, chemicals and explosives used to manufacture missiles and other weapons.
The sanctions also target 70 ships involved in Mr Putin’s “shadow fleet” operation, responsible for illicitly carrying cargo since the start of the war in Ukraine.
The Foreign Office said Mr Putin obstructed US peace efforts by launching the largest air attack of the war against Ukraine in the last fortnight, with more than 800 missiles and drones fired at the country in a single night.
On Sunday, Moscow carried out its largest aerial attack on Ukraine since the war began, an assault that hit a key government building in Kyiv for the first time.
Ms Cooper will visit the damaged building, known as the cabinet of ministers, as well as residential buildings destroyed by Russia’s attacks, the Foreign Office said.
