Earlier Thursday, Defence Secretary Ben Wallace cautioned that supplying Ukraine with fighter jets would not be a "magic wand" in the war.
Following Moscow's invasion of Ukraine last year, Britain trumpeted new legislation requiring property-ownership disclosure aimed at cracking down on Russian oligarchs and corrupt elites laundering illicit wealth.
Andrew Bagshaw, 47, and Chris Parry, 28, were reported missing in early January after having set out for the town of Soledar.
The apparent threat came in a phone call just ahead of the invasion on February 24, according to a new BBC documentary to be broadcast on Monday.
The latest wave of Russian attacks came as the Kremlin said it perceived the tanks "as direct involvement in the conflict".
Ukraine -- which had pleaded for heavy Western tanks for months -- welcomed the twin announcements, with President Volodymyr Zelensky urging they be delivered quickly.
Two British nationals were killed while rescuing an elderly woman amid heavy fighting in Soledar, Ukraine.
Poland's prime minister said on Monday his government would ask Germany for permission to send Leopard tanks to Ukraine - and planned to send them whether or not Berlin agreed.
Ukrainian President Volodymyr Zelensky said Friday there was "no alternative" but for the West to give Ukraine heavy tanks.
Former British Prime Minister Boris Johnson on Thursday urged allies to double down on sending military equipment to support Ukraine and speed up an end to the war with Russia.
Ukraine needs a "significant increase" in weapons at a pivotal moment in Russia's invasion and such support is the only way to a negotiated peaceful solution, NATO Secretary-General Jens Stoltenberg said on Wednesday.
Russia's invasion of Ukraine and a changing world order are straining ties between France and Germany as they prepare to celebrate 60 years since a post-World War II treaty sealed their reconciliation.
Prime Minister Rishi Sunak announced Saturday that his government would provide 14 Challenger 2 tanks, leading Russia to charge that Britain was worsening the conflict.
The Kremlin said on Monday that tanks Britain plans to send to Ukraine "will burn", warning the West that supplying a new round of more advanced weapons to Ukraine would not change the outcome of the war.
Former Russian President Dmitry Medvedev slammed Japanese Prime Minister Fumio Kishida for the latter's "subservience" to the United States.
Ukraine's European allies have sent Kyiv more than 300 modernised Soviet tanks since Russia invaded in February 2022.
Britain has demanded Tehran halt what foreign minister James Cleverly has called a "politically motivated" execution.
Ukraine said on Thursday its troops were holding out despite heavy fighting on a battlefield littered with bodies in a salt mining town in eastern Ukraine, where Russian mercenaries have claimed Moscow's first significant gain in half a year.
Two British nationals who were helping evacuate civilians in Ukraine have been missing since January 6.
The Taliban has said that it is merely "postponing" their education and not putting a permanent ban on it.
An auto garage in Kyiv is giving beat-up cars a second life as battle-ready vehicles for Ukraine's military, trying to plug a supply gap as the war with Russia grinds on.
Russia's defence ministry on Wednesday blamed the illegal use of mobile phones by its soldiers for a deadly Ukrainian missile strike that it said killed 89 servicemen, raising the reported death toll significantly.
Several top football players were detained by Iranian police on New Year's Eve in Tehran.
Russia continued intense attacks on Kyiv and other parts of Ukraine early on New Year's Day, following a barrage of missiles fired on Saturday, with air raid sirens wailing for hours overnight.
Residents of the Ukrainian capital Kyiv were urged to head to air raid shelters early on Friday as sirens wailed across the city, a day after Russia carried out the biggest aerial assault since it started the war in February.
General Alexei Maslov, a former Russian army chief with ties to Ukraine, died "suddenly" at the age of 69.
Russia retaliated on Tuesday against a price cap on its oil imposed by Western countries, while its forces were involved in heavy fighting around the eastern Ukrainian city of Bakhmut.
Russian Foreign Minister Sergei Lavrov gave Ukraine an ultimatum on Monday to fulfil Moscow's proposals, including surrendering territory Russia controls, or its army would decide the issue, a day after President Vladimir Putin said he was open to talks.
The Ukrainian army counted 71 strikes on the partly recaptured Kherson region on Saturday, including 41 on the city.
The pope has called for peace in Ukraine ever since Russia invaded its neighbour in February, condemning the war but seeking to maintain a delicate dialogue with Moscow.