Nicholas Drummond, a defence and security expert, believes that any plan that allows Putin to keep the territory his forces occupy could cause China to invade Taiwan.
He told the Daily Express: “Agreeing on a deal that is acceptable to both Ukraine and Russia is not going to be easy. Russia is unlikely to cede any of the territories it has gained, and Ukraine is unlikely to accept any deal whereby it loses territory to Russia.
“The third element is that any deal that allows Russia to keep territory it has taken illegally would be appeasement.
“This is not going to be straightforward.”
He added: “Any peace deal that allows Putin to end the war on his terms and keep the territory he has seized will strengthen Putin, allow him to rebuild his economy, rebuild his army, and it will make him more dangerous.
“Most important of all, if China sees that Putin’s aggression has succeeded in Ukraine, that will encourage China to invade Taiwan. That should really resonate with Trump.”
As Russia did before invading Ukraine, China has threatened the use of force against Taiwan on a number of occasions.
China considers Taiwan a breakaway province that should be “reunified” with the country. While Taiwan has stopped short of declaring outright independence, the island is a liberal democracy that wishes to govern itself free of Beijing’s influence.
China’s military has conducted numerous military drills near Taiwan in recent years.
Mr Trump has made standing up to China a key part of his appeal.
The President-elect is likely to hit China with 60 percent tariffs on all Chinese exports to the US if he abides by his promises during the election.