A top White House advisor warned Monday night that the progress Palestinians have made on security in the West Bank could be jeopardized if peace talks don’t move forward.

Dennis Ross, a senior White House Middle East advisor, pointed to improvements the Palestinians have made in security and coordination with Israel over the past two years in a speech before American Israel Public Affairs Committee activists in Florida.

“These positive developments will be difficult to sustain if the prospects for peace look less and less real,” he cautioned, according to prepared remarks released by the White House.

Ross was speaking as talks between Israelis and Palestinians have stalled, with Israel refusing to extend a freeze on settlements and the Palestinians refusing to negotiate with a reinstatement of the freeze.

He also urged that Israel not lose the chance to make peace with “unique” Palestinian leaders Mahmoud Abbas and Salam Fayyad, who have rejected violence.

The US administration has been stymied in its effort to shepherd peace talks forward after launching them in September and making them a high priority. Ross reminded the audience of “the strategic importance of peace” from America’s perspective.

But he primarily focused on Iran in his address, which he described as a preeminent threat to America.

He said that US President Obama “has consistently devoted more time to this issue than almost any other national security challenge.”

Ross noted the administration’s achievement in enacting “biting” sanctions, and detailed the many companies and countries that were pulling back on doing business with Iran to the detriment of the Iranian economy.

He emphasized that “the door for diplomacy is still open and we certainly seek a peaceful resolution to our conflict with Iran.”

But, should Iran continue to defy the international community’s demand that it halt enrichment, Ross recited Obama’s pledge that “we are determined to prevent Iran from acquiring nuclear weapons.”

Ross noted that when it came to Iran and a wide range of other issues, “this degree of coordination is unprecedented” between the US and Israel.

Stressing the strength of a relationship that observers have suggested is under strain, Ross maintained, “I have participated in these types of discussions for the last 30 years, and they have never been as intense or focused, reflecting the serious cooperation that we have today with Israel.”