MEXICO CITY (Reuters) – Mexican and U.S. officials have agreed to work together more closely to tackle record migration at their shared border, the countries’ governments said in a joint statement on Thursday, a day after high-level talks on stemming record numbers. Following a visit to Mexico by U.S. Secretary of State Antony Blinken, the countries said they would seek to strengthen a sponsorship initiative for Venezuelan, Cuban, Nicaraguan and Haitian migrants and look to tackle the root causes of migration. The delegations, who are set to meet again in Washington next month, also discussed …