Slashing its forecast for the global smartphone market by over 3 percent amid the US government's decision to ban businesses from working with Huawei, market research firm Canalys has said smartphone shipments will reach 1.35 billion units in 2019.

This is slightly below 2018's shipments that touched 1.39 billion.

"It is important to note that market uncertainty is clearly prompting vendors to accelerate certain strategies to minimise the short and long-term impact in a challenging business environment, for example, shifting manufacturing to different countries to hedge against the risk of tariffs," Nicole Peng, vice president, Mobility, Canalys, said in a statement.

"But with recent US announcements on tariffs on goods from more countries, the industry will be dealing with turmoil for some time."

Moving into 2020, most of the major mobile supply chain and the channel will have active contingency plans to mitigate Huawei's decline and be ready for 5G device roll out in many markets, the research firm noted.

Looking towards the future, Canalys has predicted positive smartphone growth in 2020 with an expected bounce back to 1.39 billion global shipments, equating to a 3.4 percent increase.

Several regions would recover faster than others due to varying lengths of the phones' life-cycles.