The United States is ready to hold talks with North Korea if the conditions are right but will also press U.N. sanctions to punish Pyongyang for its nuclear and missile tests, a senior envoy for Asia said on Saturday. "We have to be clear that under the right circumstances, we should be prepared to sit down with North Korea if they would abandon their nuclear ambitions," U.S. Assistant Secretary of State Kurt Campbell said upon arriving in Seoul ahead of talks with South Korean officials. "There have to be consequences for these provocative actions so the United States is working in the international community, with the United Nations, to put forward a robust set of sanctions and unilateral actions that are designed to send a clear message to Pyongyang," he was quoted as saying by Reuters.