Ukrainian President Volodymyr Zelenskyy has stressed that his country needs ample security guarantees to consider whether to start ceasefire talks with Russia.

Zelenskyy spoke in a joint news conference alongside the European Council's new president, Antonio Costa, in Kyiv on Sunday.

Zelenskyy emphasized that Ukraine needs enough security guarantees to strengthen its position before the agenda of possible negotiations with Russia can be set.

He noted that such guarantees need to include the supply of sufficient quantities of long-range weapons and the launch of formal procedures for Ukraine to accede to NATO.

Zelenskyy also said an invitation for Ukraine to join NATO should cover all the country's territory, including areas currently occupied by Russia.

Costa arrived in the Ukrainian capital with the European Union's new foreign policy chief, Kaja Kallas, earlier in the day, their first day in office.

Costa said the EU plans to provide Ukraine with monthly assistance worth 1.5 billion euros, or about 1.58 billion dollars, for a year, starting in January. He said the bloc will bankroll the aid with proceeds from frozen Russian assets.

Costa added that the EU stands with Ukraine "as long as necessary and whatever it takes."