Petr Pavel sounds cautious note, saying Kyiv no longer has element of surprise that led to military successes last year

• Russia-Ukraine war – latest news updates

The Czech president, Petr Pavel, a decorated retired general who was previously Nato’s principal military adviser, has privately warned Ukraine’s leadership against the disaster of a rushed counteroffensive.

In recent meetings in Kyiv with Ukraine’s president, Volodymyr Zelenskiy, and prime minister, Denys Shmyhal, Pavel cautioned that they no longer had the element of surprise that aided successful assaults on the eastern city of Kharkiv and southern region of Kherson last year.

EU member states agreed this weekend to source ammunition for Ukraine from outside the bloc, including the UK and the US, despite initial objections from France, a decision he said would increase the scope for helping Ukraine in the next weeks and months.

Europe did not have the capacity to produce the armaments it needs but it could buy it in and Zelenskiy had said he would provide qualified technicians for new ammunition factories if the EU defence industry fell short. “He said: ‘Yeah, we can do that.’”

The EU should source ammunition for Ukraine from all over the world, including countries that might not want to admit to being involved in the conflict with Russia, or with whom European capitals might feel some diplomatic embarrassment in dealing with – “there are ways how we can do it”.

Claims from the Kremlin that Ukraine had sought to assassinate Vladimir Putin through a drone strike in Moscow were “nonsense” given the defensive shield around the Russian capital, and could instead be a “pretext, for a bigger air attack on Ukraine”.

China has made a “first step” that could help the west put diplomatic pressure on Putin by backing a UN resolution describing Russia as the “aggressor”, though Pavel said he remained doubtful that Beijing could be a trusted mediator. “Does China have a real interest to push hard on Russia and to make for Russia to make concessions? I don’t think so.”

The west must be prepared for an outcome in the war short of all-out victory. “I think we should do anything at what is at our disposal to encourage Ukrainians and to support them to be successful. But internally, we should also be ready for other contingencies.”