Ukraine urgently needs to boost its air defences in the face of relentless Russian attacks, Germany’s foreign minister, Annalena Baerbock, warned as she arrived in Kyiv.

Her unannounced visit came as more than two dozen Russian drones targeted Ukraine overnight, in a reported attack that left several people injured in the eastern Kharkiv region.

“The situation in Ukraine has once more dramatically deteriorated with the massive Russian aerial attacks on civilian infrastructure, and the brutal Russian offensive in the Kharkiv region,” Baerbock said.

To protect itself from the “rain of Russian drones and missiles”, Ukraine “urgently needs a boosted air defence”, she said.

“Our support is based on the deep conviction that Ukraine will win this war,” Baerbock added.

Ukraine’s president, Volodymyr Zelenskiy, has reiterated pleas for allies to send more air defence and fighter jets to combat Russia’s air superiority as the war grinds through its third year.

He said Ukraine needed “120 to 130” F-16 fighter jets or other advanced aircraft to achieve “parity” with Russia.

Hello and welcome to the Guardian’s live coverage of the war in Ukraine. The time has just gone past 10:30am in Kyiv.

Western allies are taking too long to make key decisions on military support for Ukraine, the country’s president, Volodymyr Zelenskiy, has told Reuters as Russia is expected to step up its offensive in the north-east.

He also said he was pushing partners to get more directly in the war by helping to intercept Russian missiles over Ukraine and allowing Kyiv to use western weapons against enemy military equipment amassing near the border.

“Russians are using 300 planes on the territory of Ukraine. We need at least 120, 130 planes to resist in the sky,” Zelenskiy said.

Ukraine is waiting for the delivery of F-16 fighter jets. Zelenskiy said that if countries could not supply the planes straight away, they could still fly them from neighbouring Nato states and shoot down Russian missiles.

The Ukrainian president said Kyiv was negotiating with international partners to use their weapons to strike Russian military hardware at the border and further inside Russian territory. “So far, there is nothing positive,” he said. Zelenskiy reiterated that he had not broken agreements with allies not to use their weapons inside Russia. “We can’t put the whole volume of weapons at risk.”

Ukraine’s allies should lift such restrictions, the Lithuanian foreign minister, Gabrielius Landsbergis, said.

“From the beginning we have made the mistake of limiting the Ukrainians because it could be seen as an escalation,” he said, adding that Ukraine’s supporters were “dominated by fear of Russia … the Ukrainians must be allowed to use the equipment provided to them so that they can achieve strategic objectives. They must be able to strike Russian territory, supply lines, and military units preparing to attack Ukraine. Only one side has rules imposed on it,” he said. “We must abandon these rules that we created.”

In other news:

• One person was killed and three injured in a Ukrainian drone attack on the village of Oktyabrsky in Russia’s Belgorod region, governor Vyacheslav Gladkov wrote on Telegram on Tuesday. Belgorod lies close to the border and is considered a vital stop for Russian supply lines.

• The US treasury secretary, Janet Yellen, has urged European bank executives to step up their efforts to comply with moves to shut down Russia’s evasion of sanctions.

• A Russian delegation arrived in Pyongyang, North Korea, on Monday, according to the South Korean news agency Yonhap, and will reportedly stay until Thursday. The delegation is led by Grigoriy Rapota, a member of the International Affairs Committee of Russia’s Federation Council and chairman of the Russia-North Korea friendship parliamentary group, the Korean Central news agency said.

• Poland has arrested nine members of an alleged Russian spy ring in connection with alleged sabotage plots, prime minister Donald Tusk said on Monday. “We currently have nine suspects detained and indicted, who have been directly implicated in the name of Russian (intelligence) services in acts of sabotage in Poland,” Tusk told private broadcaster TVN24. “These are Ukrainian, Belarusian and Polish citizens,” Tusk said, suggesting some may have been recruited from criminal circles. Those detained are accused of “beatings, arson and attempted arson,” according to Tusk, who said the Russian plots concern not just Poland, but also Lithuania, Latvia and possibly Sweden.

• Humanitarian aid to Ukraine is falling back even though it needs more, the UN refugee agency, UNHCR, has warned. Karolina Lindholm Billing, its representative in Ukraine, said the four million people displaced included “some very, very vulnerable people”