The United States backed Warsaw’s assessment that the missile that landed inside Poland was fired by Ukrainian forces, but Washington blamed Moscow for causing the incident.

“We have seen nothing that contradicts President (Andrzej) Duda’s preliminary assessment that this explosion was most likely the result of a Ukrainian air defense missile”, - the White House said in a statement.

“It is clear that the party ultimately responsible for this tragic incident is Russia, which launched a barrage of missiles on Ukraine”, - it added.