Britain will provide $100 million (75.6 million pounds) to Ukraine through the World Bank, seeking to keep core state functions running and mitigate financial pressures caused by Russia's invasion, Prime Minister Boris Johnson's office said.
Britain has sought a central role in the international response to Russia's invasion of Ukraine by providing defensive military aid, arguing for tougher sanctions again the Kremlin and offering financial support.
Nevertheless, Johnson's government has faced criticism that its sanctions have been too slow and its refugee programme underwhelming.
The latest round of cash, which is in addition to $290.95 million (220 million pounds) pledged already, could be used to pay public-sector workers in Ukraine or fund pension and social security payments, British authorities said.
"While only Putin can fully end the suffering in Ukraine, today's new funding will continue to help those facing the deteriorating humanitarian situation," Johnson added.
The money will be disbursed through the World Bank Multi-Donor Trust Fund, which is designed to fast-track donations to Ukraine and is already used by some other nations.
The funding announcement comes ahead of visits to London by Canadian Prime Minister Justin Trudeau and Netherlands leader Mark Rutte, which Johnson will seek to use to strengthen the international response to the invasion.
The three leaders will hold a news conference on Monday.
($1 = 0.7561 pounds)
(Reporting by William James; Editing by Pravin Char)