TIANJIN, China (AP) — Indian Prime Minister Narendra Modi was seen clasping Russian President Vladimir Putin’s hand with the gusto of an old friend, bursting into his trademark hearty laughter. Putin grinned and chuckled, while Chinese President Xi Jinping gave a measured smile as the three leaders huddled Monday.

The trio, ringed by watchful interlocuters, chatted animatedly for a few seconds.

This happened moments before the leaders lined up for a group photo during the Shanghai Cooperation Organization in northern China’s Tianjin.

The summit represents an emerging challenge to U.S. global leadership. The security forum, originally seen as a foil to U.S. influence in Central Asia, has grown in size and influence over the years.

Xi stressed Monday that countries should reject Cold War thinking, rival power blocs and bullying, and instead protect the U.N.-centered international system. He called for a world order with multiple power centers and a more just and balanced global governance system.