The Foreign Secretary said Britain would act with Western allies to inflict 'maximum pain' on Putin's regime.
The Prime Minister of Britain, Boris Johnson has sent a stern warning to Vladimir Putin over war with Ukraine.
Johnson warned that he alongside allies will impose strict sanctions on Russia that will cripple the country's economy.
According to DailyMail, the Prime Minister will use a virtual summit of G7 leaders, including Joe Biden, Emmanuel Macron and German Chancellor Olaf Scholz, to make the case for tougher international measures against the Russian president and his cronies.
Liz Truss said British officials had drawn up a 'long list' of Russian oligarchs and companies that will face sanctions if the Kremlin orders its troops to invade Ukraine.
The Foreign Secretary said Britain would act with Western allies to inflict 'maximum pain' on Putin's regime.
Ministers are understood to be drawing up plans to hit Russian energy, defence and chemicals firms; to stop the Kremlin borrowing on the UK financial markets, and to block Russia from the Swift payment system, which accounts for about half of all high-value international payments.
The Government faced criticism this week after placing sanctions on just three oligarchs and five banks after Putin's decision to send in troops to support separatists in eastern Ukraine.
Mr Johnson insisted there was 'more to come', with measures that will 'hit Putin where it hurts'.
It came as Eurocrats agreed to the toughest sanctions in the bloc's history by striking at the heart of Putin's inner circle.
Ambassadors agreed to travel bans and asset freezes for more than 500 people accused of being linked to the Kremlin's invasion of Ukraine.
They include high-profile officials such as defence minister Sergei Shoigu, Putin's chief of staff Anton Vaino, and fiery foreign ministry spokesman Maria Zakharova.
And the White House said Mr Biden had allowed sanctions to move forward against the company that built the Russia-to-Germany Nord Stream 2 gas pipeline and against the company's chief executive.
Germany said on Tuesday it was indefinitely suspending the project, after Mr Biden said Putin had launched 'the beginning of a Russian invasion of Ukraine'.
The pipeline is complete but has not yet begun operating.
British MPs have called for action against 35 oligarchs identified by Russian opposition leader Alexei Navalny as 'key enablers' of the 'kleptocracy' run by Putin.
Only one of the 35 – oil baron Gennady Timchenko – has so far been sanctioned by the UK.
Others on the list, which was read out to Parliament by Liberal Democrat MP Layla Moran, include Chelsea FC owner Roman Abramovich and former Arsenal FC investor Alisher Usmanov.
Miss Truss declined to say whether Mr Abramovich could be the target of sanctions, but suggested that many more oligarchs would be targeted.
'We have a long list of those complicit in the actions of the Russian leadership,' she said.
'Should Russia refuse to pull back its troops, we can keep turning up the heat, targeting more banks, elites and companies of significance.
'This is about inflicting pain on Putin and degrading the Russian economic system over time, targeting people that are close to Putin. What we have to do is make it as painful as possible.'
Mr Johnson held talks with senior City figures about ways to tighten the screws on Russian businesses and individuals with links to the Kremlin.
The PM told the Commons that the Government was 'bringing forward' the next wave of sanctions which would 'stop all Russian banks, all oligarchs, all Russian individuals raising money on London markets'.
Ministers are also drawing up plans to stop the Kremlin borrowing on the UK financial markets.
Tory MP Bob Seely said the 'tide of dirty money' entering the UK from Russia was 'damaging' the country.
Labour leader Sir Keir Starmer said it was time to end the 'era of oligarch impunity' and ensure 'this country will no longer be homes for their loot'.
Mr Johnson acknowledged the impatience of many to move faster, but said it was vital that it was done on a co-ordinated international basis.
'On all these measures it is very important to remember that they are more effective when all financial centres move forward together, and that is what the UK has been organising,' he said.