SEOUL, South Korea (AP) — North Korean leader Kim Jong Un is facing the toughest challenges of his nine-year rule. His country’s fragile economy was battered this year by pandemic-related border closings and natural disasters. He’s also likely concerned about President-elect Joe Biden’s expected new approach on North Korea. Kim is expected to use next month’s ruling party congress, the first of its kind in five years, to bolster internal unity and lay out new economic and foreign policies. While few question Kim’s grip on power, there is still room for things to get worse. Some experts say Kim does not have many options other than to further squeeze his people for more labor and patience.