Ms Truss urged fellow G7 foreign ministers at the start of a three-day meeting to commit to renewed waves of sanctions for as long as President Putin's troops remain in Ukraine.

She called on countries to agree that the restrictions should stay in place until there was a complete withdrawal and peace agreed, as well as for financial and technical assistance to help Ukraine rebuild.

Kyiv 'sets Russian ship on fire in Black Sea' - follow latest Ukraine war updates

Meanwhile, the UK is arguing that Ukraine needs a "clear pathway" to NATO standard equipment, including the immediate provision of urgently-needed artillery shells, as well as training and expertise from NATO members, and a plan for transition to this equipment by the end of the summer.

The G7 ministers were joined at the meeting in Schleswig-Holstein, Germany, on Thursday evening by the foreign ministers of Ukraine as well as Moldova - to discuss how they could be supported in the face of Russian aggression, the UK government said.

Moldova has been on a state of alert following recent explosions in the Russian-backed breakaway Transnistria region of the country, which borders Ukraine.

Ms Truss said: "Putin is humiliating himself on the world stage. We must ensure he faces a defeat in Ukraine that denies him any benefit and ultimately constrains further aggression.

"To help Ukraine, we need to go further and faster.

"The best long term security for Ukraine will come from it being able to defend itself. That means providing Ukraine with a clear pathway to NATO-standard equipment."

On Saturday, Ms Truss is due to travel to meet NATO foreign ministers in Berlin.

She will call for the UK and its allies to develop a "strengthened and modernised" NATO ready to tackle global threats, the Foreign Office said.

The foreign secretary's visit to Germany comes after Boris Johnson travelled to Sweden and Finland to sign mutual defence agreements - which would see Britain come to the countries' aid if they are attacked by Russia.

Less than 24 hours later, Finland's leaders announced that they support the country joining NATO.

The Nordic country has previously remained neutral for fear of antagonising Russia, with which it shares an 830-mile border.

But public support for joining the Western military alliance has grown since Mr Putin began his attack on Ukraine in February.

The Kremlin responded to Finland's decision to embrace NATO by warning that it will be forced to take retaliatory "military-technical" steps.

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