LONDON, England (CNN) -- British Prime Minister Gordon Brown announced Monday his country will step up sanctions on Zimbabwe's government and will call on the European Union to do the same.
The move comes after China and Russia used their veto power Friday to block a U.N. resolution imposing sanctions on Zimbabwe's President Robert Mugabe, and 11 senior members of his government.
At a news conference Monday, Brown called the vetoes "difficult to justify" and "unfortunate," adding that "the vast majority of the people in the world want to see action against the Zimbabwe regime."
"We will now ourselves step up our sanctions," he said. "We will ask the European Union, at its meeting in a few days' time, to add a number of names" and corporate entities to its sanctions list, Brown said.
"I have this morning asked the treasury to work with the Financial Action Task Force to track the wealth and the assets that are owned by members of the Mugabe regime which we know are held in different continents" including Asia, Africa, and Europe, he said, "so that we are in a position to take tougher action against them at a later date."
Brown also vowed to return to the United Nations with a new resolution "if mediation does not succeed" in Zimbabwe.
The United States pushed the resolution last week after Mugabe ignored the Security Council's appeal to postpone a presidential runoff election.
The June 27 vote initially was intended to be a runoff between Mugabe and Morgan Tsvangirai, leader of the Movement for Democratic Change, but Tsvangirai withdrew days before, saying Mugabe's supporters had orchestrated a campaign of beatings, intimidation and murders against Tsvangirai supporters.
Voters described intimidation and violence, and said they were forced to report the serial numbers of their ballots to Mugabe's government. But Zimbabwean officials denied any intimidation.
According to a draft version, the U.N. resolution would have slapped a travel ban on Mugabe and the others, frozen many of their assets and imposed an international arms embargo on the regime.
The measure received nine votes in favor -- the minimum to pass. But two of the five negative votes were from Russia and China, who as permanent members of the Security Council have veto power.
Chinese Ambassador Wang Guangya said Friday his nation believes the international community should allow talks in South Africa on the Zimbabwe situation a chance to work before imposing sanctions.
"China has always maintained the best approach to solve a problem is negotiation and dialogue," Wang said. "To use or threaten to use sanctions lightly is not conducive to solving the problem."
Russian Ambassador Vitaly Churkin said Friday the Security Council would have overstepped its responsibilities had it approved the resolution.
"Recently, in the positions of a number of council member states, we have seen an ever-more-obvious attempt to take the council beyond its chartered prerogatives and beyond maintaining international peace and security," Churkin said. "We believe such practices to be illegitimate and dangerous, leading to a realignment of the entire U.N. system."
"This draft is nothing but the council's attempt to interfere in the internal affairs of states," contrary to its charter, he said.
U.S. Ambassador Zalmay Khalilzad said Friday the United States was "disappointed" at the veto.
"China and Russia have stood with Mugabe against the people of Zimbabwe... for reasons that we think are not borne out by the facts on the ground," he said.
Zimbabwean Ambassador Boniface Chidyausiku said his nation has been a victim of "incessant meddling" from the international community, and insisted that sanctions imposed in previous years have been responsible for its currently underperforming economy and the suffering of its people.
The Zimbabwean people, he said, are "committed to resolve their differences."