WASHINGTON, Oct 15 (Reuters) - The United States for the time being will stay in an international nuclear deal with Iran, US Ambassador to the UN Nikki Haley said on Sunday, adding that the Trump administration wanted to weigh a "proportionate" response to Tehran's actions on the world stage."I think right now, you're going to see us stay in the deal. Because what our hope is that we can improve the situation. And that's the goal," Haley said referring to worries over Iran's ballistic missile tests, international arms sales and state-sponsored terrorism.Haley, interviewed on NBC's "Meet the Press," also said the reason the United States was looking closely at the Iran nuclear deal is because of escalating tensions over North Korea's nuclear weapon development. "What we're saying now with Iran is don't let it become the next North Korea."