Bronislaw Komorowski has been sworn in as Poland's new president after a snap election forced by the death of Lech Kaczynski in an air crash.
Jaroslaw Kaczynski, the bereaved identical twin of the late president, was not in parliament for the inauguration.
In his inaugural address, Mr Komorowski vowed to support Poland's government in developing ties within the EU and NATO, with strategic partner the US, as well as with Russia.
'We want to reinforce, inspire and make the Old Continent (Europe) more dynamic', the 58-year-old told both houses of parliament as he was sworn in as Poland's fourth democratically-elected president.
Mr Komorowski named Brussels, Paris and Berlin as the destinations for his first official foreign visits.
Asked why his rival Jaroslaw Kaczynski stayed away, a spokesman for his conservative Law and Justice (PiS) party said: 'Civic Platform politicians made brutal verbal attacks on president Lech Kaczynski when he was alive and some continue to do so even after his death.'
Lech Walesa, Poland's first democratically-elected president after the collapse of communism, did attend his swearing-in, along with former president Aleksander Kwasniewski.
A liberal with political roots in the governing Civic Platform (PO) party of Prime Minister Donald Tusk, Mr Komorowski won the 4 July second round of the presidential election scoring 53.01% of the vote.
Parliamentarians held a minute's silence to honour the victims of the 10 April air crash, which claimed the lives of Lech Kaczynski, his wife and 94 other Polish dignitaries, including top military personnel and the central bank governor.
They were killed when their presidential jet crashed in bad weather in western Russia en route to ceremonies marking a World War II Soviet massacre of Polish officers.
