WARSAW, Poland (AP) — German Chancellor Angela Merkel is visiting Warsaw amid calls by Polish officials that Germany pay Poland billions of dollars for damage inflicted by the Nazis during World War II.

Polish Prime Minister Mateusz Morawiecki welcomed Merkel during a ceremony Friday ahead of discussions between the two governments.

The talks come amid some strains between the two neighboring states.

Polish officials say Germany owes Poland up to $850 billion (743 billion euros) for the damage inflicted during World War II. Germany says Poland has no legal basis for the claims.

Another key issue straining ties is Poland's vocal opposition to Nord Steam 2, a German-Russian gas pipeline project which Warsaw says will give Russia excessive control in Europe, hurting Poland and Ukraine in particular.