President Donald Trump and Russia's Vladimir Putin have shaken hands at a summit in Vietnam.

The two leaders were spotted on video greeting one another ahead of an Asia-Pacific Economic Cooperation summit gala dinner in the coastal city of Danang.

Mr. Trump and Putin were expected to hold a formal meeting on the sidelines of the summit. But as the president was about to land on Friday, the White House announced no meeting would take place.

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Press Secretary Sarah Huckabee Sanders blamed scheduling conflicts.

But Secretary of State Rex Tillerson said earlier this week that the pair would not meet unless they had something substantive to discuss. CBS News' Major Garrett reported that the Russians were open to meeting, but the U.S. wasn't satisfied there would be serious engagement on issues including Ukraine, Syria, as well as Russian meddling in the U.S. presidential election.

Mr. Trump is attending annual Asia-Pacific Economic Cooperation summit in Vietnam, one of several summits he is planning to attend during a five-country Asian tour. Formal talks are set to begin Saturday.

Earlier in the day Friday, Mr. Trump used a speech in Vietnam to denounce multilateral agreements embraced by the region and deliver what appeared to be a rebuke to China, railing against trade practices he says have put Americans out of work.