This question consists of six sentences of a passage. The first and sixth sentences are given as S1 and S6. The middle four sentences in each have been jumbled up and labelled as P, Q, R and S. You are required to find the proper sequence of the four sentences and mark your response accordingly.

S1: The United States is working a new round of sanctions against North Korea, U.S. National Security Advisor Jake Sullivan said on Thursday, as Pyongyang forges ahead with banned missile development and signals a possible new nuclear test.
P: Mr. Sullivan, who spoke via live video link, did not elaborate but said Washington was committed to using pressure and diplomacy to entice North Korea into giving up its nuclear arsenal.
Q: "We have a new set of sanctions measures coming forward as we speak," he told a conference in Seoul organised by the U.S.-based Center for Strategic and International Studies and the South Korean JoongAng media group.
R: The "North Star" of U.S. Joe Biden's North Korea policy is the denuclearisation of the Korean peninsula, and it remains steadfast in pursuing that goal while being flexible in working with partners on how to achieve it, he said.
S: He pointed to increased cooperation between the United States, South Korea, and Japan, which have increased joint military drills.
S6: The United States is also working on a more "visible" regional presence of its strategic assets, Mr. Sullivan said, referring to major weapons such as aircraft carriers and long-range bombers.