MOSCOW (Bloomberg) - Russian President Vladimir Putin said he has no personal ties to his American counterpart Donald Trump as he lamented the crisis in relations between the former Cold War rivals.

"We have zero personal relationship. We've only met once,'' Putin said on Wednesday at the Russian Energy Week conference in Moscow. The Russian leader praised Trump as someone with a strong character who will "never be anybody's hostage," but said the relationship between Russia and the US has been poisoned by a domestic political fight in America.

Tensions have steadily risen between the two powers since Trump took office early this year despite the US president's campaign promises of better ties. The two countries have targeted each other in tit-for-tat diplomatic measures after America toughened sanctions on Russia for alleged interference in last year's US presidential election.

Russia has repeatedly denied findings by US intelligence agencies that it intervened in an effort to hurt Democratic challenger Hillary Clinton and ultimately to help elect Trump.

Putin took issue with Trump on the crises involving North Korea and Iran. He said the Iranian side is complying with the agreement curbing its nuclear activities and that Russia will continue defend the pact as the US threatens to walk away from it.

The Russian president also urged dialogue between Washington and Pyongyang, saying that threats like Trump's warning last month in New York that the US would "totally destroy" the isolated Communist state if it strikes at it are leading to a "very dangerous dead end."

Putin revealed that in 2001, North Korean leader Kim Jong Un's father, Kim Jong Il, told him that North Korea had an atomic bomb which could easily hit Seoul. Trump's rhetoric doesn't help.

"Those who try to speak to North Korea from a position of strength only shore up the North Korean regime," he said.