North Korea must take "concrete" steps towards denuclearisation before benefiting from any relaxation of international sanctions, Downing Street has said.
Speaking on the eve of US President Donald Trump's historic summit with North Korea's leader Kim Jong Un in Singapore, Number 10 said the UK welcomed the fact that the meeting was taking place.
Prime Minister Theresa May's official spokesman said any agreement coming out of the summit should lead to "complete, verifiable and irreversible" denuclearisation by the Pyongyang regime.
The PM's spokesman told a regular Westminster media briefing: "We have welcomed the fact that the summit is taking place.
"We need to see an agreement that brings about the complete, verifiable and irreversible denuclearisation of the Korean peninsula.
"We will continue to work with our international partners to strictly enforce existing sanctions until such time as North Korea turns its commitments into concrete steps towards denuclearisation."
Mr Trump and Mr Kim are set to meet on Tuesday morning in the first summit of its kind between a leader of North Korea and a sitting US president.
The pair are due to meet one-on-one with translators in a session that could last up to two hours before they open the meeting to their respective advisers.
Mr Trump, who arrived in Singapore on Sunday, has voiced optimism about the meeting, saying that he thought "things can work out very nicely".