The rivalry between Russia and Ukraine and the former's relations with NATO have reached “dangerous” levels, Foreign Minister Mevlüt Çavuşoğlu said Thursday.

"We will not ignore our principles and close relations with Ukraine just because we have extensive relations with Russia. In many difficult equations like this, we do whatever the spirit of the time and our national security require. It's hard work, but that's what diplomacy is for," Çavuşoğlu said at the closing ceremony of the virtual International Security Academy organized by the International Relations Association.

Kyiv has been battling a pro-Moscow insurgency in two eastern regions bordering Russia since 2014, shortly after the Kremlin annexed Ukraine's Crimean Peninsula.

Western countries accuse Russia of plotting to invade Ukraine and massing around 100,000 troops on the ex-Soviet country's borders. Moscow has denied those claims.

Earlier President Recep Tayyip Erdoğan said that Turkey could mediate between Ukraine and Russia amid increasing tensions in the region.

Turkey, a NATO member, has criticized Moscow's annexation of Crimea and voiced support for Ukraine's territorial integrity. The United States and United Nations General Assembly view the annexation as illegal as well.

Fighting between Ukrainian government forces and pro-Russian separatists in Donbass has killed more than 13,000 people since 2014, according to the United Nations.

The region is one of the several sources of friction between Russia and Ukraine.

Çavuşoğlu went on to say that NATO has also transformed, noting that it was trying to adapt itself to new developments and that the focus was on strengthening the political dimension in the NATO 2030 process.

As the country with the second-largest military among NATO members and the fifth-greatest contributor to the alliance's operations and missions, he emphasized that Turkey plays an active role in these efforts.

"There are efforts by some countries to present the EU as an alternative to NATO. This is not constructive and unrealistic. The indivisibility of trans-Atlantic security is our fundamental principle," he said.

Speaking on Turkey’s foreign policy, he underlined that Ankara is pursuing a "realistic foreign policy" based on the superiority of the diplomatic initiative over a wide geography.

"We have a proactive approach to diplomacy, not reactive, without letting events rule us.”

Çavuşoğlu stressed that the global security environment was getting increasingly fragile. "After the Cold War, great power competition is fueling tensions in different regions such as Ukraine, the Balkans, the Black Sea, Taiwan, and the South China Sea. The effects of relatively modern challenges such as climate change, terrorism, cyberattacks, irregular migration and the pandemic are being felt everywhere," he said.

He underlined that in the current environment of rapid change, one of the most important points in international relations that have remained constant is the international order established after World War II.

"While software updates come to our mobile devices every few weeks, the fact that the international system has not been updated for 80 years makes it difficult for the system, especially the U.N., to find solutions to problems," he said.

Çavuşoğlu pointed out that in the early days of the coronavirus pandemic, the "need for multilateralism" had emerged once again.

"We cannot say that a significant distance has been covered on this road in the last year. However, we see that concepts such as multilateralism and solidarity come to the fore, at least at the level of discourse," he said.