Polish Foreign Minister Radoslaw Sikorski says Warsaw is offering a $290,000 reward for information leading to the arrest of those responsible for the killing of Polish engineer Piotr Stanczak in Pakistan.

Sikorski said Tuesday Poland also submitted a formal note to the U.S. State Department requesting assistance in capturing the killers and plans to issue an international warrant for their arrest.
Stanczak was kidnapped by Pakistani Taliban militants in Pakistan's volatile northwest last September and was beheaded by his captors on Saturday.

Meanwhile, the speaker of Poland's Senate Bogdan Borusewicz canceled a visit by his Pakistani counterpart, Mohammedmian Soomro, who was due to arrive in Warsaw on Thursday.

Borusewicz said his decision was not an "unfriendly" move towards Pakistan, but rather a reaction to the fact that a fellow countryman had been murdered.

A graphic video of the killing was released on Sunday.

The video shows Stanczak appealing to the Polish government to withdraw its troops from Afghanistan before two masked men cut off his head.

One of the masked men says Stanczak was killed because the Pakistani government refused to release detained militants before a deadline.

On Monday, the United Nations repeated its appeal for the release of a U.N. refugee agency official, John Solecki, who was kidnapped one week ago in southwestern Pakistan.  

Some information for this report was provided by AFP and AP.