The "Coalition of willing countries" – a group of around 25 countries working together to achieve a sustainable peace in Ukraine, is meeting in a digital meeting on Saturday, according to 10 Downing Street.
The time has come for "concrete commitments" towards Ukraine, is the message from the British Prime Minister, according to his office.
"If Russia finally comes to the table, then we must be ready to monitor a ceasefire to ensure that it is a serious and lasting peace", says Starmer in a statement and continues:
"If they don't, then we must strive to increase the economic pressure on Russia to secure an end to this war".
Sweden's Prime Minister Ulf Kristersson is participating in Saturday's meeting. In addition to several European countries, the EU and NATO, Canada, Australia and New Zealand are also expected to participate.
Putin announced on Thursday that he has major reservations about agreeing to a ceasefire. Starmer calls it an attempt to delay and says it shows that Putin is not serious about achieving peace.
In the Ukrainian newspaper European Pravda, Starmer writes on Friday that the UK will stand by Ukraine's side "not just today or tomorrow, but for the next 100 years".
Starmer also writes that a peace must be of the kind that "Ukraine's heroes deserve".
