WARSAW, Poland -- Polish opposition party leader Jaroslaw Kaczynski said Monday he will run in summer elections to replace his twin brother, the incumbent president who was killed in a plane crash.

Jaroslaw Kaczynski said he will run to continue the mission of his brother and others killed in the crash.

"The good of Poland is a common duty that requires an ability to overcome personal suffering, to undertake the task despite a personal tragedy," Kaczynski said.

"This is why I have taken the decision to run for the president of Poland. I have the family's support in this decision."

The elections were moved up to June 20 after President Lech Kaczynski, his wife Maria and 94 others — including top civilian and military leaders — were killed April 10 in Smolensk, Russia, en route to World War II observances. The president's term was to expire in December and elections had been planned for the fall.

The incumbent had been expected to seek a second five-year term.

Jaroslaw Kaczynski's closest family are his mother, Jadwiga and niece Marta, the daughter of the late president.