Syrian President Bashar al-Assad warned in comments broadcast Friday that the fall of his government or the breakup of his country will cause a “domino effect” that will fuel Middle East instability for years. It was his sharpest warning yet about the potential for Syria’s civil war to affect neighboring states.

In Moscow, Russia’s president said the Syrian conflict has become “a massacre” that must be stopped through peace talks and repeated the Kremlin’s firm rejection of calls for Assad’s ouster.

The Syrian regime is under growing pressure from an increasingly effective rebel movement that has managed to pry much of northern Syria away from the government and has made headway recently in the south, capturing territory and military bases.

In the interview with the Turkish TV station Ulusal Kanal aired Friday, Assad accused his neighbors of stoking the revolt against his rule, saying, “We are surrounded by countries that help terrorists and allow them to enter Syria.” But he warned that those countries may eventually pay a price.

“Everybody knows that if the disturbances in Syria reach the point of country’s breakup, or terrorist forces control Syria, or if the two cases happen, then this will immediately spill over into neighboring countries first, and later there will be a domino effect that will reach countries across the Middle East,” he said.

The president also used the interview to quash rumors that he had been killed by one of his guards in the capital, Damascus, saying he is living as usual in Syria and is not hiding in underground shelters.

Russia, a close Assad ally, has shielded Damascus from U.N. sanctions and largely has stood by the regime, although it has also signaled that it is not tied to his remaining in power. At the same time, it has refused to back calls for Assad to step down, and has instead pushed for talks with the opposition.

Speaking to the German public television network ARD in remarks released by the Kremlin on Friday, Russian President Vladimir Putin repeated Moscow’s firm rejection of calls for Assad’s ouster.

“We believe that it is necessary to bring everyone to the negotiation table,” he said.

In Syria on Friday, a barrage of rockets slammed into the contested Barzeh district on the northeastern edge of Damascus, killing at least five people, while rebel fighters overran an army checkpoint near the southern border with Jordan, activists said.

— Associated Press