U.S. Energy Secretary Rick Perry (second from left) and Saudi Energy Minister Khaled al-Falih (right) arrive for a signing ceremony of a memorandum of understanding on carbon management between Saudi Arabia and the United States in Riyadh on Dec. 4. (Fayez Nureldine/AFP/Getty Images)

Energy Secretary Rick Perry will fly to London this week to discuss a nuclear cooperation agreement with senior officials from Saudi Arabia, which is planning to build two reactors along the Persian Gulf, according to an administration official.

Perry was originally scheduled to take part in meetings with Mexican officials, but Mexico’s president, Enrique Peña Nieto, canceled his visit to Washington.

The meeting in London comes shortly before a scheduled visit to the United States by the Saudi Crown Prince Mohammed bin Salman.

United States has long pressed Saudi Arabia to agree to a nuclear cooperation agreement – known as a 123 agreement for the clause in the Atomic Energy Act – that would include strict bans on the enrichment of uranium and the reprocessing of spent fuel.

The United Arab Emirates agreed to such a deal in the final days of the George W. Bush administration. A South Korean consortium is currently building four reactors in the UAE.

But Saudi Arabia has insisted that it be allowed to enrich its own supplies of uranium as a matter of national sovereignty.

It remained unclear whether Perry was carrying a proposal to the London meeting. He traveled to Saudi Arabia last fall.

The kingdom has received delegations from five major nuclear reactor companies, including the bankrupt Westinghouse. The Canadian real estate and industrial conglomerate Brookfield has submitted a plan to buy Westinghouse.

The nuclear cooperation agreement has divided nonproliferation policymakers, some of whom see the sale of nuclear reactors to Saudi Arabia as too risky given the instability in the region. Others say that if U.S. firms are not allowed to compete because of a missing cooperation deal, then Russian or Chinese companies with fewer concerns about enrichment, reprocessing or proliferation might step in.