US Secretary of State Antony Blinken was expected to meet the leaders of Turkey and Greece on Saturday at the start of a week-long trip aimed at tamping down tensions that have spiked across the Middle East since Israel's war with Hamas began in October. The Biden administration's top diplomat kicked off his talks by meeting Turkey's foreign minister Hakan Fidan in Istanbul and was also scheduled later to meet President Tayyip Erdogan, a strong critic of Israel's military actions in Gaza.