The body of Poland's First Lady, Maria Kaczynska, is to be flown to Warsaw to lie in state alongside that of her husband, President Lech Kaczynski.
Poland has seen an outpouring of grief since the couple and scores of other top Polish officials died in a plane crash in western Russia on Saturday, BBC News repoted.
The Polish First Lady died alongside her husband and 94 other people in a plane crash in west Russia on Saturday morning.
The delegation was on its way to pay tribute to some 20,000 Polish officers executed by Soviet secret police in 1940.
Poland has declared a 7-day period of national mourning. The presidential couple are likely to be buried together after a funeral on Saturday, according to RIA Novosti.
In Warsaw, the acting president, Bronislaw Komorowski, moved Monday to start appointing replacements for the many posts left vacant in the presidential office. He appointed a retired general, Stanislaw Koziej, as new National Security Bureau chief and said Koziej's first task would be a review of the travel rules for top military officials.
Both Russia and Ukraine declared a day of mourning Monday, as Poles struggled to come to terms with the tragedy that eliminated so many of their government and military leaders, Dallas Morning News reports.