Israel says the Islamic militant group Hamas has rejected a proposal to exchange prisoners in return for two Israeli soldiers' remains held since the 2014 Gaza War, which killed over 2,200 Palestinians and 73 Israelis.

Israeli official Lior Lotan told a security conference Tuesday that Hamas is violating the norms of conflict by refusing a swap.

The fate of the soldiers' remains is an emotional issue in Israel, where military service is mandatory. The militant group is also believed to be holding two Israeli citizens.

Hamas had no immediate comment.

Israel has carried out a series of lopsided prisoner swaps with militant groups in the past.