Ukraine opposition leader Poroshenko seeks softer diplomacy to achieve peace

(Reuters) - Former Ukrainian President Petro Poroshenko called on Thursday for a softer approach to diplomacy with the United States after a spat between Kyiv and Washington and offered to visit foreign capitals to improve the country's standing.

Poroshenko was president from 2014 to 2019 and is now the opposition leader in parliament. He remains a political rival to current President Volodymyr Zelenskiy, who beat him by a landslide in a 2019 election.

He said Zelenskiy should stop "stadium behaviour" in dealing with U.S. President Donald Trump, who branded the Ukrainian leader a "dictator without elections" for staying in power beyond his mandate and refusing to call a wartime election.

"This form of combat does not work in Ukraine's favour, however eloquent the arguments may be," he said in a video message.

"Discussion with Trump requires diplomatic mastery, patience and calm so as not to react to his every statement," Poroshenko said, standing alongside a row of military vehicles.

Parliamentarians, he said, could help with diplomacy.

"I am ready to go to Brussels or even Washington to save the situation," he said. "And there should be other experts and parliamentarians with authority in society."

Authorities, he said, had tried to block plans by opposition parliamentarians to travel abroad to boost Ukraine's diplomacy.

Poroshenko offered no criticism of the failure to hold an election, saying it could not be done "while there is no peace".

He issued a new call for the creation of a coalition government of national union and an end to the "monopoly" of the president's office and political party in the country.

In Kyiv on Thursday, Zelenskiy told the U.S. envoy for Ukraine and Russia, Keith Kellogg, that Ukraine was ready to work quickly to produce a strong and useful agreement on investments and security with the United States.

Zelenskiy's verbal clash with Trump came as U.S. and Russian officials held initial talks on ending the nearly three-year-old war -- Ukraine was not invited -- and Kyiv's rejection of a U.S. proposal to develop rare earths in Ukraine.

Poroshenko was hit last week by official sanctions imposed on security grounds, including an asset freeze and a ban on withdrawing capital from the country.

He has been under investigation in connection with various allegations, including charges of helping Russian-backed separatists who seized large parts of eastern Ukraine in 2014 and a scandal over corrupt practices in military procurement.

(Reporting by Ron Popeski; Editing by Sandra Maler)