The UK will send an additional 650 short-range missiles to Ukraine to help in its fight against invading Russian forces.
The new package of aid comes as Ukrainian President Volodymyr Zelensky made another impassioned plea for further support from allies at a defence summit at the Ramstein air base in Germany.
Mr Zelensky said he was grateful for the military support Ukraine had received but urged allies to authorise the used of Western-supplied long-range missiles on targets inside Russia.
Also joining the summit is UK Defence Secretary John Healey, who will be announcing the £162 million package which includes the supply of further Lightweight Multirole Missiles (LMM).
Mr Healey said ahead of the summit that the new UK package would give an "important boost" to Ukraine's air defences and showed the government was "stepping up" its support.
But Prof Michael Clark, the former director-general of the defence and security think tank Royal United Services Institute, has told BBC Radio 4's Today programme the supply will likely be "exhausted within a couple of months". He said Ukraine needed "more of everything at the moment" given the intensity of Russian advances and bombardments.
Lightweight with precision guidance, LMMs have low collateral damage and a range of more than 6km, according to their manufacturer Thales.
In July, UK Prime Minister Sir Keir Starmer committed to sending £3bn a year to Ukraine for as long as needed. Since the start of Russia's invasion in February 2022, the UK has committed a total of £12.7bn including £7.6bn in military support.
Mr Zelensky arrived in Ramstein on Friday morning, just days after a Russian missile attack on the city of Poltava in central Ukraine killed at least 51 people.
In his appeal to international allies, he said: "It’s important that every support package that is announced is promptly put to work on the battlefield without any delay.
"The fighting in the Donetsk region depends on this - if [Russian President Vladimir] Putin does not have any achievements here, he will not have any achievements anywhere." The United States, Kyiv's largest backer, has also announced it will provide a further $250m (£189.9m) in military aid.
Mr Zelensky also called on Western allies to authorise the use of long-range missiles to attack targets within Russia, saying it was the only way to bring about an end to the war.
In a direct appeal, he said: "Now we hear that your long range policy has not changed. We think it is wrong that there are such steps. We need to have this long-range capability not only on the occupied territory of Ukraine but also on the Russian territory."
The UK previously said Ukraine had a "clear right" to use British-provided weapons for "self defence" which "does not preclude operations inside Russia", following Kyiv's surprise cross-border incursion last month.
However, this excludes the use of long-range Storm Shadow missiles in territory outside Ukraine's internationally-recognised borders.
The US provided long-range missiles to Ukraine earlier this year, but like Kyiv's other Western allies these have not been authorised for use on targets inside Russia.
