US President Donald Trump stressed that the future of Western civilisation is at stake in a keynote speech in the Polish capital Warsaw on Thursday. Citing Poland as an example of a country ready to defend Western freedoms, he warned against the threats of "terrorism and extremism", reported BBC.

Earlier, reacting to North Korea's recent missile tests, Trump called the country's behaviour "very, very dangerous".

"It's a shame they're behaving this way — they're behaving in a very, very dangerous manner and something will have to be done about it," said Trump while addressing a news conference with Polish President Andrzej Duda outside Warsaw's Royal Castle in Poland, CNN reported.

While answering a question about military action against North Korea, Trump said, "I have some pretty severe things that we are thinking about. That doesn't mean we are going to do it. I don't draw red lines."

"As far as North Korea is concerned, I don't know, we will see what happens," Trump added.

Trump arrived in Warsaw late Wednesday for a 16-hour visit that includes a keynote address to the Poles from Krasinski Square, the site of a monument commemorating the 1944 Warsaw Uprising against the Nazis.

Meeting with Putin

Trump will meet Russian President Vladimir Putin on Friday, right after both sides have made their policies clear on North Korea's first launch of an intercontinental ballistic missile.

The US president's highly anticipated sit-down with his Russian counterpart comes at a time when relations between the two nations are at a low point.

It is important to note that Trump has shown a reluctance to take a hard line against Russia amid an ongoing investigation by US intelligence agencies to determine whether Moscow interferred in the 2016 presidential elections.