On Tuesday, North Korea successfully launched a two-stage intercontinental ballistic missile - a missile that could travel more than 4,000 miles.
Drawing an implicit contrast with Russia, Mr Trump pledged that the U.S. would never use energy to coerce eastern and central European nations.
In a nod to the conservative values he shares with Poland's controversial ruling Law and Justice party, Trump will also call on the West to defend its traditions.
It was probably an innocent mistake, but when you leave the US President hanging, it looks awkward.
"Obviously, we have critical relations with China, India, the other members of the G20, and that's really what this meeting is about". First, he declined to endorse the US intelligence community's conclusion that Russian Federation had interfered in last year's presidential election.
Mr Trump is also calling on Russian Federation "to join the community of responsible nations in our fight against common enemies and in defense of civilization itself".
Trump, speaking to the network after his father's speech in Poland, noted that the president praised the ally for holding up to its commitment to North Atlantic Treaty Organisation, and that sends a sign to the rest of the world, Trump said.
Trump responding when a reporter asked why he wouldn't agree with his intelligence agencies that Russian Federation meddled with the 2016 elections said: "I heard it was 17 agencies, I said boy that's a lot -do we even have 17 agencies, let's check that".
Another handshake fail! President Donald Trump appeared to be snubbed while trying to shake hands with Poland's first lady, Agata Kornhauser-Duda.
President Barack Obama chided Poland's government during a visit here previous year. Trump also has yet to nominate a director of the National Park Service.
"Poland becomes", a senior White House official told reporters ahead of the address, "in many respects, a symbol and a metaphor for the sacrifices required to preserve a civilization". "They have been fake news for a long time", Trump said on Thursday.
Maybe Trump is having pre-Putin meeting jitters?
"Everybody can contribute in their own way, and we can work together in a great way", said Trump, and if somebody fails to do so, then quite frankly, they're not being great allies". But it sure is another uncomfortable handshake moment for the United States president, who's known for his vigorous grip, which at times looks like he's trying to rip the other person's arm off.
Trump also met with Japanese and South Korean leaders Thursday evening, on the eve of the G20 summit, which runs Friday and Saturday.