Lloyd Austin, speaking at the Ukraine Defence Contact Group, praises troops’ courage in ‘hard and dangerous fight’. This live blog has closed

Russia’s foreign minister, Sergei Lavrov, held a meeting with his Chinese counterpart, Wang Yi, in Kazakhstan’s capital Astana, the Russian state news Tass agency reported on Monday.

It said the ministers were meeting to discuss the implementation of Russian-Chinese agreements reached during Vladimir Putin’s state visit to China last week, and events in Iran, whose president and foreign minister were killed in a helicopter crash on Sunday.

Ukraine’s president says air defences must quadruple to halt Russian advance as morale falls among troops

The Ukrainian president, Volodymyr Zelenskiy, has said he expects Russia to step up its offensive in the north-east and warned Kyiv has only a quarter of the air defences it needs to hold the front line.

Russian forces, which had made only moderate advances in recent months, launched a surprise assault in Kharkiv region on 10 May that has resulted in their biggest territorial gains in a year-and-a-half.

The country’s foreign ministry said the supply of long range weapons to Ukraine by the UK and US had led to an escalation in the conflict

A long-range Ukrainian strike on the Moscow-controlled Belbek airbase in occupied Crimea destroyed three Russian warplanes and a fuel facility near its main runway this week, US commercial satellite company Maxar said.

The company cited satellite imagery taken on Thursday as showing that two MiG-31 fighter jets and an Su-27 fighter jet had been destroyed. It said one MiG-29 fighter aircraft also appeared to have been damaged.