A Ukrainian drone attack has caused another major fire at the Russian oil refinery in the city of Tuapse – the third attack on the Black Sea port in less than two weeks. Vladimir Putin, Russia’s president, condemned it as a “strike against civilian infrastructure” but Kyiv says the campaign is designed to disrupt Russia’s oil industry and slash revenues that help Moscow fund the war – making such facilities a legitimate target in war. In this strike, dense black smoke again rose from the direction of the Tuapse refinery, which has annual production capacity of about 12m tonnes.

The refinery halted production on 16 April because of drone damage to the port that made it impossible to ship its production, industry sources told Reuters. The head of the Tuapse district, Sergei Boyko, on Tuesday ordered people living near the refinery to evacuate by bus to a local school. After an attack on 20 April, black rain fell on the town and a popular beach resort, leaving an oily residue. Putin has sent an emergencies minister to Tuapse.

King Charles has given a speech to the US Congress in which he made pointed reference to the defence of Ukraine, write Chris Stein and Caroline Davies. Charles said: “In the immediate aftermath of 9/11, when Nato invoked article five for the first time, and the UN security council was united in the face of terror, we answered the call together – as our people have done so for more than a century, shoulder to shoulder, through two world wars, the cold war, Afghanistan, and moments that have defined our shared security. Today, Mr Speaker, that same, unyielding resolve is needed for the defence of Ukraine and her most courageous people. It is needed in order to secure a truly just and lasting peace.”

Last week, the king’s son Prince Harry, Duke of Sussex, visited Kyiv and urged “American leadership” to honour its obligations in the Ukrainian conflict because the US was one of the countries that convinced post-Soviet Ukraine to give up nuclear weapons in exchange for security commitments. Trump rebuffed those comments, saying Harry “is not speaking for the UK”, but will find it more difficult to dismiss remarks by the king, of whom he is an avid fan.

The acting US ambassador to Ukraine will step down from her post after less than a year in the job, the state department has said, amid a lull in US-brokered efforts to achieve a ceasefire and end Russia’s invasion. The Financial Times, quoting unnamed sources, said Julie Davis had grown frustrated with Donald Trump over his lack of support for Ukraine – her predecessor left for the same reason – but the state department said she was simply retiring from the department.

The Hungarian election winner, Péter Magyar, has proposed a meeting with Volodymyr Zelenskyy, the Ukrainian president, to discuss minority rights of ethnic Hungarians in western Ukraine. Magyar does not share defeated rival Viktor Orbán’s overt hostility towards Ukraine and support for Russia, but still opposes fast-track Ukrainian membership of the EU and says Kyiv’s treatment of ethnic Hungarians in western Ukraine will be key to rebuilding ties. Orbán was accused of exaggerating and distorting the extent of grievances between Ukraine’s ethnic Hungarian population and the Kyiv government. Ethnic Hungarians are among those fighting for Ukraine against Russia. They include the head of Ukraine’s drone force.