President Trump hinted Thursday that his administration has considered "pretty severe" responses to North Korea's intercontinental ballistic missile test this week.

"I don't like to talk about what I have planned," Trump said during a joint press conference with Polish President Andrzej Duda in Warsaw. "But I have some pretty severe things that we're thinking about. That doesn't mean we're going to do them."

North Korea's ICBM test, which Pyongyang touted as a success, drew swift condemnation from the U.S. and escalated tensions in an already fraught situation.

Trump took a swipe at his predecessor while explaining why he would not telegraph his thinking on North Korea.

"I don't draw red lines. President Obama drew a red line, and I was the one that made it look a little bit better than it was," Trump said, referring to Obama's 2012 claim that Syria's use of chemical weapons would cross a "red line" for the U.S. and warrant military reprisal.

Obama took criticism when Syria later used chemical weapons on civilians and the U.S. did not respond militarily.

Trump authorized a cruise missile strike against a Syrian airbase in April after Syria launched a chemical attack on civilians.

"But that could've been done a lot sooner, and you wouldn't have had the same situation that you have right now in Syria. That was a big mistake," Trump added.

The White House has stayed largely silent on how it plans to counter an increasingly aggressive North Korea. Although Trump has leaned on China to use its influence in Pyongyang to curb North Korea's nuclear activity, the president has signaled he does not believe China has done enough to rein in its neighbor.

"I think we'll just take a look at what happens over the coming weeks and months with respect to North Korea," Trump said. "It's a shame that they're behaving this way, but they are behaving in a very, very dangerous manner, and something will have to be done about it."