Secretary of State Rex Tillerson ended on Thursday his several hour visit to Beirut, which was limited to discussing Lebanon’s unresolved maritime border dispute with Israel. Tillerson did not take any decisive stance regarding his country’s mediation over so-called Block 9 which has started with a proposal made by Acting US Assistant Secretary for Near Eastern Affairs David Satterfield last week. His initiative is based on a previous American proposal. Known as the “Hoff Line,” the proposal calls for Lebanon to acquire 550 square kilometers of the disputed 860 square kilometers that Lebanon insists is part of its maritime border, and abandon the remaining part to Israel. Israeli-Lebanese tensions have spiked in recent months because of Israeli plans to build a wall at the border, and because of Lebanons decision to begin exploring for oil and gas in Block 9 in disputed waters. During their talks with Tillerson, Lebanese leaders reiterated their rejection of Israeli assaults on Lebanese sovereignty. “We had very good discussions in all of our meetings today, this is an extremely important issue to Lebanon, it is important to Israel as well to come to some agreement so that private companies can go to work offshore and determine what in fact might be available in terms of natural resource development and how to get started in moving forward,” the US official said following talks with Lebanese Prime Minister Saad Hariri at the Grand Serail. “We had a good exchange over our lunch meeting thinking about creative ideas on how to wreck the stalemate and move forward, so we will continue to be very engaged with both parties. We have asked no one to give up anything, we are rather looking for a solution,” said Tillerson. He also expressed optimism that negotiations would lead to a final settlement if both sides were consensual. President Michel Aoun earlier told Tillerson that Lebanon was committed to preserving calm on its southern border and urged Washington to play an "effective role" to help resolve Beiruts land and maritime disputes with Israel. Aoun urged the US to "work on preventing Israel from continuing its assaults on Lebanese sovereignty" by land and sea. He said Lebanon was holding onto its internationally recognized borders, and rejected Israeli claims over parts of its Exclusive Economic Zone. During his short visit to Beirut, Tillerson also held talks with Speaker Nabih Berri.