NATO and the European Union say that they want to improve their cooperation in response to "new threats" posed by Russia's assertive policies, by Islamic State militants in Syria and Iraq, and by waves of illegal immigrants arriving on the EU's southern shores via Libya.
The statements came from NATO and EU foreign ministers who gathered on May 14 for a second and final day of talks in the Turkish resort city of Antalya.
EU foreign-policy chief Federica Mogherini told the meeting that the EU and NATO were "different in nature" but faced similar challenges.
She said the main focus at the talks would be the tensions with Russia over Ukraine and the EU's migrant "crisis in the south."
The ministers were also expected to discuss whether NATO should maintain a presence in Afghanistan after the current NATO-led training mission ends, probably at the end of 2016.
Regarding the conflict in eastern Ukraine, Mogherini said EU and NATO ministers needed to work on "the way to implement, on our side, the Minsk agreement," referring to the cease-fire deal signed in February by Russia, Ukraine, and the pro-Russian separatists in eastern Ukraine.
Mogherini said EU ministers also needed to better coordinate their support for cease-fire monitors in eastern Ukraine from the Organization for Security and Cooperation in Europe (OSCE).
General Philip Breedlove, NATO's supreme allied commander, told reporters at the gathering on May 14 that the Minsk agreement was under strain because of repeated cease-fire violations.
He said the way to move forward on Ukraine was, first, to ensure that the cease-fire set out in the Minsk agreement is implemented.
Those remarks echoed a call by U.S. Secretary of State John Kerry for Moscow to support the cease-fire plan in eastern Ukraine.
Kerry told the gathering in his opening remarks on May 13 that now is a "critical moment for action by Russia and separatists to live up to the Minsk agreement."
Kerry was also briefing the EU and NATO ministers about his May 12 talks in Sochi, Russia, with President Vladimir Putin and Foreign Minister Sergei Lavrov.
Kerry was also scheduled to meet with Ukrainian Foreign Minister Pavlo Klimkin and Turkish Prime Minister Ahmet Davutoglu.
Earlier, NATO chief Jens Stoltenberg told the gathering in Turkey that the alliance faced "evolving" challenges in both the east and the south.
He said Russia must stop supporting the separatists in eastern Ukraine and withdraw all of its forces from that country.
Ahead of the gathering, Turkish Foreign Minister Mevlut Cavusoglu said the summit would be Ankara's opportunity to share its concerns about Islamic State (IS) militants in neighboring Syria and Iraq.
Cavusoglu noted that Turkey is the only NATO member state that neighbors areas under the control of IS militants in both Syria and Iraq.
He said that situation was "not sustainable" and "a big threat to Turkey."
U.S. Ambassador to NATO Douglas Lute described an "arc of instability" around the east and south of the alliance.
He said that the "maybe failed state of Libya" had become a funnel for illegal immigration from Africa, as well as refugees trying to flee the war zones of Syria and Iraq.
NATO as an organization has not been highly active militarily in the south recently, although all of its member states are part of the U.S.-led coalition against the IS group.
NATO also has sent Patriot antimissile systems to defend Turkey from possible attacks from war-torn Syria.
NATO is considering a request from Iraq for help training its army.
But it says the security situation in Libya must improve before it can help train Libyan security forces.
With reporting by Reuters, AP, AFP, CNN, and BBC