Greening, the British Department for International Development secretary, said her agency would provide a further 18 million pounds in support for immediate humanitarian needs in DR Congo.
The money will provide 100,000 people with three months of emergency food assistance, as well as access to clean water, essential household items and emergency education for more than 130,000 people, she said.
African leaders who convened in Uganda over the weekend demanded that the M23 group withdraw from Goma as a condition of initiating negotiations.
Mixed signals have come from M23 leaders and soldiers this week.
South African Minister of Defense Nosiviwe Mapisa-Nqakula told CNN that she had met with the defense ministers of Tanzania and Namibia this week following a request for help from DR Congo, a fellow member of the Southern African Development Community.
Mapisa-Nqakula said the defense ministers have called for a hybrid African Union force to be placed in eastern DR Congo to stabilize the situation.
She said that they would come up with specific plans of action next week, but that Tanzania had already volunteered to send in a battalion and South Africa to provide logistical support.
She said they had been disappointed with the actions of MONUSCO, the U.N. peacekeeping force in eastern DR Congo that essentially looked on when the M23 entered Goma.
"We warned the United Nations about this and asked them to strengthen their mandate before M23 took Goma. All they could do is wave as M23 entered," she said.
"We are very disappointed, and it's not like we didn't warn them," she said. "We saw that this was going to happen."
She also accused the M23 of multiple human rights violations.
South Africa has more than 1,000 soldiers as part of the MONUSCO contingent.
The latest unrest continues a cycle of violence and misery in eastern DR Congo, a mineral-rich region at the epicenter of political and ethnic conflict involving its neighbors to the east, Uganda and Rwanda.
The area has been embroiled in violence since 1994, when Hutu forces crossed the border from Rwanda fearing reprisals after the genocide in that country.
The M23 group was named for a peace deal of March 23, 2009, which it accuses the government of violating. The soldiers, mostly Tutsis, became part of the national army through that accord.
However, they broke away from the Congolese army in April, complaining they weren't being promoted as promised, and because of a lack of pay and poor conditions.