During their conversation on Tuesday, Rau and Cleverly also talked about bilateral relations and energy security, the Polish foreign ministry said.
Cleverly wrote in a tweet on Tuesday that Russian President Vladimir Putin "won’t break the Ukrainians or our resolve to stand with them."
He said: "Putin failed to capture Ukrainian towns and cities with tanks, now he tries cowardly drone attacks. These are the desperate acts of a man losing a war on the battlefield."
Britain's government last month pledged to "match or exceed" its 2022 military support to Ukraine next year.
It said at the time that the UK was the second-largest military donor to Ukraine, after the United States, committing £2.3 billion in 2022, according to the gov.uk website.
Wednesday is day 238 of the Russian invasion of Ukraine.
(gs)
Source: PAP