Priti Patel has warned Yemen is "on the brink of a catastrophic disaster", amid claims that the UK's aid effort is being undermined by arms sales to Saudi Arabia.
The International Development Secretary urged other countries to join the UK in helping to deal with the cholera outbreak in the war-torn country, which has affected hundreds of thousands of people.
Labour welcomed the UK's efforts to push the international community to respond to the humanitarian crisis, but said aid can only have a limited impact while the Government puts "profits of arms exporters before lives" in Yemen.
Three United Nations agencies, including the World Health Organisation (WHO), said last month that Yemen was experiencing the "world's worst cholera outbreak".
They reported around 400,000 cases of suspected cholera and nearly 1,900 associated deaths were recorded within the last three months.
The agencies added that two years of hostilities had "crippled" vital health, water and sanitation facilities - thereby creating the "ideal conditions" for diseases to spread.
Thousands of people have been killed in the conflict, which has pitched a Saudi-led coalition in support of the internationally-recognised government of Yemen against Iran-backed Houthi rebels.
The UK has continued to allow sales to the Saudis, with more than £3.3 billion worth of arms having been licensed since the bombing began in March 2015.
The High Court last month ruled that the UK can carry on selling arms to Saudi Arabia, despite allegations they are being used to commit "war crimes" in Yemen.
Ms Patel said: "Yemen is on the brink of a catastrophic disaster if the world continues to close its eyes to the urgent help three-quarters of people across the country desperately need.
"The response by the international community is the only hope Yemeni people have to survive.
"UK aid is providing life-saving food for 1.7 million people, as well as clean water, emergency healthcare and sanitation to contain the cholera outbreak and prevent it from spreading further.
"The international community must follow Britain's lead and join our efforts and step up support to avert famine and cholera engulfing the country."
The Department for International Development said the UK's work seeks to help 300,000 people access safe, chlorinated water in a bid to prevent further spread of cholera.
They added that support from the UK also includes providing medical supplies, such as chlorine tablets and hygiene kits, to 500,000 people and medical facilities to rehabilitate 250,000 people.
Shadow international development secretary Kate Osamor said: "The UK is right to be stepping up its aid effort and must push the international community to do more to secure peace and respond to the humanitarian situation.
"But Priti Patel forgets to mention the single biggest thing the UK Government could do to alleviate the situation in Yemen: stop selling arms to Saudi Arabia, now.
"As long as our Government continues to put the profits of arms exporters before lives in Yemen, UK aid can only have a limited impact."