While Zelenskiy has held numerous talks with Biden, French President Emmanuel Macron and Turkish President Tayyip Erdogan since late February, the accumulation of discussions in just one day is not a regular event.
Zelenskiy said in his nightly video address that he expects some "important results" this week from a series of international events that will tackle the situation in Ukraine.
Erdogan's office said the Turkish leader had a call with Russian President Vladimir Putin on Sunday, in which he had called for a quick end to the conflict.
There are no peace talks and no end in sight to the deadliest conflict in Europe since World War Two.
