Czech President Petr Pavel speaks during an interview in Prague
Czech President Petr Pavel reacts after an interview with Reuters at Prague Castle in Prague, Czech Republic, May 12, 2023. Reuters

Ukraine's planned counteroffensive to win back territory occupied by Russia has a good chance of success but may bring high casualties if Russia uses its prepared defences well, Czech President and former NATO general Petr Pavel said on Friday.

Pavel, 61, said in an interview that Ukraine needs support for NATO and European Union entry but joining either will be a lengthy process, though talks on the EU accession could start this year.

Pavel, who was Czech army chief and also the principal military adviser to the NATO secretary-general in 2015-2018, said Ukraine would eventually get Western fighter jets it has been calling for but it was impossible to deliver them in time for the upcoming offensive, and there were higher priorities such as ammunition.

"There is certainly high hope that the Ukrainian counteroffensive will be successful, because Ukraine is motivated, well prepared, its troops are experienced and certainly do not succumb to such deficiencies as the Russian army," Pavel said at Prague Castle, the seat of the Czech presidency.

The Russian army had severe problems in logistics and morale, but a collapse of defences should not be expected, he said.

"Russia has had time to prepare a relatively high-quality and in-depth defence in several lines, which, if used effectively, will cost... Ukraine large casualties," he said.

It was impossible to say what size of territory Ukraine could win back as various scenarios were open, he said.

"Things do not always go according to wishes and plans but I think that the chance for a significant Ukrainian success is really high."

Pavel, decorated for saving a French unit during a peace-keeping mission in Croatia in 1993, refused to speculate on when the counteroffensive may start, but said recent Ukrainian attacks on Russian infrastructure and troop concentration spots were marks of preparations.

Ukraine has asked for fast-track membership of NATO, but Pavel said it would take time.

"Supporting Ukraine's entry into the EU and NATO should be our long-term target," Pavel said when asked what NATO should tell Ukraine at a July summit in Vilnius.

"I am not saying it has to be in any given time horizon, because preparations for entry into both these institutions is very complicated, requires long preparation and meeting a whole list of criteria, but we should help Ukraine with it."

Negotiations on EU entry could realistically start at the end this year, he said, which would give Ukraine a springboard to closer cooperation, helping post-war reconstruction, and speed up the alignment with EU standards.

Ukraine's President Volodymyr Zelenskiy had hoped the EU would put Ukraine on a rapid road to membership, but the EU has not given any rigid time lines.

"When it comes to NATO... the more stable Ukraine is economically, the bigger chance it will be prepared earlier for entry into NATO," Pavel said.