Ukrainian President Volodymyr Zelensky is asking Russian President Vladimir Putin for a face-to-face meeting, roughly four years after Russia invaded Ukraine, amid the countries' roughly 11-year-long war. 

Zelensky said in the letter Thursday it would be "wrong to simply wait" until the conflict between the two countries again becomes a central focus of attention from the United States, which has shifted its focus to the conflict in Iran. 

Peace between Russia and Ukraine, Zelenksy wrote, could only come through direct discussions, the BBC reported. 

The Ukrainian leader also asked for a ceasefire during these proposed negotiations, but Putin ruled out the possibility. Putin said he is willing to reach an agreement with Ukraine, but compromises are needed, which would include surrendering territory to Russia. Ukraine has ruled out ceding the territory Russia is asking for.  

President Donald Trump encouraged a meeting between the two leaders.