Representatives from 21 countries had gathered in the British capital on Wednesday to discuss ways to help Yemen address its security problems and bolster its faltering economy.
Miliband said that as part of commitments made by Yemen during the conference was a pledge to start talks with the International Monetary Fund.
These would aim to help Yemen put together a programme of economic reforms, the foreign minister said.
Speaking at the news conference, Abu Bakr al-Qirbi, Yemen's foreign minister, said: "We talked in transparency, we all understand the challenges facing us.
"This meeting has expressed strong commitment, and there is expectation from us.
"We are at beginning of the road, and want to come out of here with instruments that will help us to achieve goals. We will work in partnership with US."
Hillary Clinton, the US secretary of state, said: "We share concern for Yemen's sovereignty and will ensure it will remain untouched.
"Ultimately the future of yemen is up to Yemenis themselves, they need to solve their own problems, but where we can be of assistance we will do so."
Yemen is battling an independence movement in the south of the country and Houthi fighters in the north, as well as the domestic al-Qaeda affiliate, al-Qaeda in the Arabian Peninsula.
Mohamed Vall, Al Jazeera's correspondent in Sana'a, the Yemen's capital, said the country's tribes have recently rallied behind the government in its fight against al-Qaeda.
"But any heavy-handed security crackdown on al-Qaeda that leads to civilian deaths in rural areas could turn the tide against the government - something that could limit the government’s military options against extremism," Vall said.
Gordon Brown, the British foreign minister, arranged the Yemen summit in London in the wake of a failed attempt to attack a US airliner last month.
US authorities say Umar Farouk Abdulmutallab, a 23-year-old Nigerian who is accused of trying to blow up the plane, was trained for the attack in Yemen by al-Qaeda in the Arabian Peninsula.
Following Wednesday's talks, Britain's foreign ministry said Yemen's Western and Gulf donors would meet in Riyadh in Saudi Arabia on February 27-28, for more discussions.