Poland's defence minister, Radoslaw Sikorski, has resigned, the ministry's spokesman told Polish news agency PAP on Monday (February 5). PAP gave no reason for the resignation, but Polish media has reported a series of conflicts between Sikorski and Polish prime minister Jaroslaw Kaczynski over the last few days. Polish newspapers have reported that Kaczynski and his twin brother Lech, the president, have criticised Sikorski for his handling of negotiations with the United States over the stationing of a U.S. missile defence system on Polish soil. Sikorski's resignation comes just before a decision is to be made on the proposal. A major reinforcement of troops under the NATO mission in Afghanistan is also expected to be installed in February. Sikorski has also been in conflict with the head of Polish military intelligence, who has urged Kaczynski to dismiss him, newspapers have reported. A spokesman for the Polish government declined to comment on the report.