President Obama offered a spirited defense of his national security agenda Friday at a press conference in which he also warned Republicans they would be making a mistake in forcing a government shutdown showdown over ObamaCare funding.

In one of his final events before leaving for a eight-day vacation in Martha’s Vineyard, Obama also explained his defense of former Treasury Secretary Larry Summers — a candidate to lead the Federal Reserve — and called on the House to pass the Senate’s immigration bill.

But the president’s comments were primarily focused on foreign policy, with Obama unveiling a sweeping set of new disclosures and safeguards to address concerns over National Security Agency surveillance programs.

The controversy surrounding those programs has contributed to falling poll numbers for Obama, who after a bruising summer dominated by a series of contraversies has seen his approval ratings fall to the low 40s.