The next two weeks will show whether progress is possible in resolving the military conflict in Ukraine, US President Donald Trump said.

"I would say within two weeks, we're going to know one way or the other," Trump said during an interview with radio host Todd Starnes.

The US president added, however, that if Russian President Vladimir Putin doesn't end the war by the aforesaid deadline, Washington will likely have to change tactics.

Trump commented also on his meeting with Ukrainian President Volodymyr Zelenskyy at the White House on August 18. According to him, the Ukrainian leader looked very good and showed determination in the fight.

Zelenskyy is fighting with all his might, and this is a tough war, the US president noted.