Turkish President Recep Tayyip Erdogan on Thursday called for intensified effort to end the war in Ukraine, adding that there were "no losers in a just peace".

Erdogan said Turkey was trying to pursue "a balanced policy" because of its heavy reliance on Russian energy imports.

Turkey has supplied Ukraine with armed drones and other weapons, but Erdogan also enjoys a close working relationship with Russian President Vladimir Putin.

"We should intensify our diplomatic efforts for a long-lasting ceasefire," Erdogan told reporters at the end of a NATO summit focused on Russia's invasion of its pro-Western neighbour.

The Madrid gathering saw the US-led military alliance formally invite Finland and Sweden to join the bloc.

Their membership applications were held up until the last moment by Erdogan, who sought guarantees that the Nordic countries would join Turkey's fight against banned Kurdish militants and to swiftly extradite suspects.

The dispute was resolved by a 10-point memorandum, signed on Tuesday, that appeared to address many of Erdogan's concerns.

But Erdogan said he now expected the two countries to implement the deal in full.

"We have strongly emphasised the message that we expect genuine solidarity from our allies, not only in words but also in action," Erdogan said.

New countries' membership applications must be approved by all NATO member states, and ratified by the countries' respective parliaments.

Erdogan warned that Sweden and Finland's implementation of the 10-point agreement would decide whether he forwarded their application to the Turkish parliament for ratification.

"If they fulfil their duties, we will send it to the parliament. If they are not fulfilled, it is out of the question," he said.