Secretary Tillerson arrives in London ahead of Libya, North Korea talks

Secretary of State Rex Tillerson arrived in London on Thursday ahead of a special summit hosted by British Foreign Secretary Boris Johnson to discuss North Korea and Libya.

Tillerson was greeted by U.S. Ambassador to the United Kingdom Woody Johnson -- also the owner of the NFL's New York Jets.

Fresh off the latest United Nation sanctions, Tillerson will meet with Johnson and French Foreign Minister Jean-Yves Le Drian to talk North Korea.

"[Tillerson] never misses an opportunity in bilateral, multilateral settings to raise North Korea and the need to increase pressure," according to State Deptartment Director of Policy Planning Brian Hook, including calling on all nations to end guest worker visas for North Korean citizens.

However, the focus of the summit will be on achieving peace in Libya, where the U.S. is aiming for some movement. Attendees include U.N. Special Representative for Libya Ghassan Salamé of Lebanon, appointed in June, and delegations from France, the United Arab Emirates, Italy and Egypt.

"You are seeing a lot of unity in terms of where we need to go and how we can get there," Hook said.

With a new U.S. administration and a new U.N. special representative, Hook said, "We are trying to give structure and energy and encouragement to all of the factions in Libya and are hopeful that new players will help achieve that," although ultimately that it will be a "Libyan-led process."

Libya has been fractured since a 2011 uprising toppled dictator Moammar Gadhafi. Gadhafi was later seized and executed by rebels in October 2011.

The country is currently split into east and west with separate militias and political factions.