Refugees and migrants aboard the passenger ferry Blue Star Patmos arrive at the port of Piraeus, near Athens, Greece, Feb. 1, 2016. Almost 6,000 refugees who registered at the islands of Lesbos and Chios arrive at the Port of Piraeus. Hundreds keep making the crossing from Turkey to the Greek islands despite bad weather conditions. (Xinhua/Marios Lolos)

BERLIN, Feb. 16 -- German Chancellor Angela Merkel on Tuesday warned against national closing-border solutions and vowed to fight for the joint European Union plan to limit flows of refugees to Europe.

Merkel said the success of the upcoming EU summit in Brussels on Thursday and Friday depended on whether EU nations could cooperate with Turkey in the refugee crisis, referring to a joint EU-Turkey action plan agreed on last November.

"I will put all my strength on Thursday and Friday to make the European-Turkish approach turns out to be the right way to go on," said Merkel at a joint press conference with visiting Israeli Prime Minister Benjamin Netanyahu.

She also warned against the alternative measures suggested by the so-called Visegrad Group of Hungary, Poland, Slovakia and the Czech Republic to close the Greek-Macedonian-Bulgarian border, saying that such national solutions would have serious consequences for Greece, the European Union and thus the Schengen zone.

Merkel meanwhile said that the EU summit was not about agreeing on new quotas for a fair distribution of refugees in Europe.

Merkel has been under huge pressure at home to reduce refugee inflows. She is also increasingly isolated within the EU because many European partners believe that the refugee crisis has been worsened by Germany's policy to leave its door open for refugees.