Jersey has followed the UK in freezing the assets of five Russian banks and three oligarchs after troops from Moscow moved into two separatist regions in eastern Ukraine.
The Kremlin has described the troops as peacekeepers after Moscow recognised the areas as independent states.
But the Prime Minister said he has no doubt it amounts to a 'renewed invasion'.
Boris Johnson has outlined a worst-case scenario.
"Then a European nation of 44 million men, women, and children would become the target of a full-scale war of aggression - waged without a shadow of justification."
Speaking to MPs earlier, he also insisted that the situation is being monitored globally.
"What happens in Ukraine, what is happening in Ukraine now is being watched around the world and the echoes will be heard in Taiwan and East Asia and throughout the world."
UK Prime Minister Boris Johnson in Ukraine for crisis talks
The individuals that have had sanctions imposed - who are described as having 'high net worth' - will also be banned from travelling to Britain.
The full details of the Jersey sanctions imposed can be found here.
External Relations Minister, Senator Ian Gorst, says Jersey's government takes its obligations as a responsible jurisdiction extremely seriously.
"These new designations will take effect immediately. Any assets held in Jersey in relation to these individuals and financial institutions must be frozen without delay.
Jersey is a robustly regulated finance centre with a record of helping to enforce the agreed actions of the international community. Notices have been published in the Jersey Gazette to advise of these new designations, to remind the industry of their legal obligation to freeze assets and economic resources, and report on any connection to them.
Officers continue to work closely with UK counterparts, and we are ready to take further measures to ensure Jersey’s response is in line with the international community."
Parked cars damaged in Victoria Avenue crash
L'Ecume II: Lewis Carr jailed for 20 months for fatal collision at sea
Guernsey's former Chief Minister admits making indecent images of children
Minister approves 42 sheltered homes at nursing home
Jersey potato farm to be the site of Channel Islands' largest roof solar array
Emergency work on Bagot Road due to suspected gas leak
Jersey court to allow sentencing remarks to be filmed
St Saviour to get new public park
