Ukraine's President Volodymyr Zelensky. (Photo: AP/Efrem Lukatsky)

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.